Method of making a reinforcing mat for a pultruded part

ABSTRACT

A method of preparing a reinforcing structure for use in manufacture a pultruded part where the reinforcing structure is pulled through a pultrusion die in a continuous longitudinal pull direction. The method includes arranging a plurality of first reinforcing fibers in a transverse direction and attaching a permeable transport web of staple fibers to the first reinforcing fibers such that the portion of the first reinforcing fibers oriented in the direction transverse comprises at least 40% of a volume of materials comprising the reinforcing structure.

Cross-Reference to Related Applications

[0001] The present application is a continuation-in-part of U.S.application Ser. No. 09/597,453, entitled Pultruded Part and Method ofPreparing a Reinforcing Mat for the Part, filed Jun. 20, 2000, whichclaims priority of U.S. Provisional application serial No. 60/155,258filed Jun. 21, 1999.

FIELD OF THE INVENTION

[0002] The present invention relates to a method of making thereinforcing mat for molded articles.

BACKGROUND OF THE INVENTION

[0003] Pultrusion is a known technique in which longitudinallycontinuous fibrous elements, which can include reinforcing fiber and/ora mat, are combined into a resin-based structure. The process generallyinvolves pulling reinforcing fibers and/or reinforcing mats through abath of thermoset resin and then into a heated forming die. The heat ofthe die cures the resin as the part is pulled through the die on acontinuous basis.

[0004] The mat and reinforcing fiber are typically flexible andconformable textile products since they need to conform to the profileof the die. The mat and reinforcing fiber are typically glass products,while the resin matrix is usually, but not necessarily, a thermosettingpolyester. Mat material is generally in the form of a non-woven,felt-like web having glass fibers randomly placed in a planar swirlpattern.

[0005] During the pultrusion process, reinforcing fibers typicallyreferred to as rovings comprise groupings of hundreds or thousands ofmicrons-diameter filaments, that mechanically behave like flexible rope.The filaments are flexible because the diameter of each filament is sosmall. The flexibility of the individual filaments imparts sufficientflexibility to the reinforcing fibers to fulfill the processingrequirements of pultrusion. In a pultrusion profile, the mat and rovingsconstitute the reinforcement, while the resin constitutes the binder ofthe solid composite. After pultrusion, the rovings are held together bythe cured or semicured resin matrix, providing the pultruded part withrigidity.

[0006] The longitudinal strength of pultruded parts is very high sincethe majority of the fibers are the longitudinally extending reinforcingfibers that are pulled through the die. However, the transverse strengthof pultruded parts is generally minimal because conventional mat fibersextend in random directions and only a small proportion of the totalfiber component extends in the transverse direction.

[0007] Conventional mats also have a number of problems that interferewith the efficiencies of the pultrusion process. First, the mat isrelatively expensive. Second, the mat is difficult to form into therequired shape for complex parts. The compressed thickness of the matalso represents a lower limit on the thickness of sidewalls, increasingthe amount of resin needed for a given part. Lightweight continuousfilament or “swirl” mats are easier to shape, but provide minimalstrength, and are more prone to ripping at the die entrance due to lowwet tensile strength. The choice of mat is, in part, a compromisebetween the necessity for bending to shape, the required strength of thepultruded part, and the pulling strength of the reinforcing mat.

[0008] U.S. Pat. No. 5,005,242 (Vane) reports a reinforcing mat having aplurality of superimposed layers. Each layer consists of a plurality ofuni-directional non-woven yams or threads laid side-by-side. The yams inat least some of the different layers extend in different directions.The layers of reinforcing material are stitched together by knitting soas to hold the yams in fixed position relative to one another. The matdisclosed in Vane exhibits strength primarily in the direction of theunidirectional yams.

[0009] U.S. Pat. No. 5,908,689 (Dana et al.) reports a mat adapted toreinforce a thermosetting matrix material. The mat includes a primary,supporting layer having a plurality of randomly oriented essentiallycontinuous glass fiber strands. The primary layer is about 1 to about 20weight percent of the mat on a total solids basis. A secondary layer ispositioned upon and supported by a surface of the primary layer. Thesecondary layer includes a plurality of glass fiber strands having amean average length of about 20 to about 125 millimeters. The strands ofthe primary layer are entangled with the strands of the secondary layerby needling the primary layer and the secondary layer together.

[0010] U.S. Pat. No. 5,910,458 (Beer et al.) reports a mat adapted toreinforce a thermosetting matrix material. The mat includes a primarylayer of generally parallel, essentially continuous glass fiber strandsoriented generally parallel to a longitudinal axis of the mat. Theprimary layer is about 45 to about 90 weight percent of the mat on atotal solids basis. A secondary layer includes a plurality of randomlyoriented, generally continuous glass fiber strands. The strands of theprimary layer are entangled with the strands of the secondary layer byneedling.

[0011] U.S. Pat. No. 4,058,581 (Park) reports adding discontinuousfibers to the resin bath. Similarly, U.S. Pat. No. 5,324,377 (Davies)reports mixing cut fibers in the resin bath to form a homogeneous massof resin and fibers. The continuous fibers, the cut fibers and the resinare then passed through a die and become integrated into a pultrudedpart.

[0012] In order for the reinforcing mat to pass through the die with thelongitudinal fibers, it is necessary for the mat to have a sufficientlongitudinal strength so that it does not tear as it is pulled throughthe die. Furthermore, the mat must have a sufficient shear strength sothat it does not twist or skew allowing one side edge of the mat to movein advance of the other side edge. If such twisting or skewing occurs,the mat will become distorted in the part and the mat eventually willbreak down and the part will be unusable.

BRIEF SUMMARY OF THE INVENTION

[0013] The present invention is directed to a method of preparing areinforcing structure for use in manufacture a pultruded part where thereinforcing structure is pulled through a pultrusion die in a continuouslongitudinal pull direction. The method comprises arranging a pluralityof first reinforcing fibers in a transverse direction and attaching apermeable transport web of staple fibers to the first reinforcing fiberssuch that the portion of the first reinforcing fibers oriented in thedirection transverse comprises at least 40% of a volume of materialscomprising the reinforcing structure.

[0014] In one embodiment, the method comprises arranging the pluralityof first reinforcing fibers such that the portion of the firstreinforcing fibers oriented in the direction transverse to the pulldirection comprises at least 50% of the volume of the materialscomprising the reinforcing structure. In another embodiment, the firstreinforcing fibers are arranged into one or more overlapping layers offirst reinforcing fibers. The staple fibers can have a length of about ½inch to about 4 inches. Alternatively, the staple fibers have a lengthof about 0.01 inches to about 12 inches.

[0015] In one embodiment, the staple fibers comprise a weight of about60 grams per square meter to about 300 grams per square meter beforeattachment to the first reinforcing fibers. In another embodiment, thestaple fibers comprise a weight of about 10 grams per square meter toabout 1200 grams per square meter before attachment to the firstreinforcing fibers.

[0016] The permeable transport web can optionally comprise heat-fusiblefibers. In another embodiment, the permeable transport web comprises atleast two different polymeric fibers, each comprising a different glasstransition temperature. In one embodiment, the two polymeric fiberscomprise a glass transition temperature of about 350° F. and about 270°F., respectively. In another embodiment, the permeable transport webcomprise a plurality of first polymeric fibers comprising a first glasstransition temperature a plurality of bi-component fiber. The firstcomponent comprises the first glass transition temperature and a secondcomponent comprises a second glass transition temperature less than thefirst glass transition temperature. The bi-component fibers optionallycomprise a core-sheath configuration.

[0017] The reinforcing structure preferably comprises in-planemechanical and directional stability. The permeable transport webpreferably comprises a plurality of fibers at least a portion of whichare randomly entangled with the first reinforcing fibers. In anotherembodiment, the permeable transport web comprises a plurality of fibersat least a portion of which are thermally bonded to the firstreinforcing fibers.

[0018] In one embodiment, the first reinforcing fibers are spaced apartand attached together by a continuous stitching fiber. The stitchingfiber comprises glass fibers, natural fibers, carbon fibers, metalfibers, ceramic fibers, synthetic or polymeric fibers, composite fibersincluding one or more components of glass, natural materials, metal,ceramic, carbon, and/or synthetics components, or a combination thereof.In another embodiment, a binder attaches the permeable transport web tothe first reinforcing fibers. In one embodiment, the binder comprisesone or more of a specialized latex binder diluted in a water carrier, apolyvinyl acetate emulsion, or a crosslinking polyvinyl acetateemulsion.

[0019] The reinforcing structure includes a plurality of perforationsthrough the permeable transport web and extending between the firstreinforcing fibers. In one embodiment, the reinforcing structurecomprises a permeability of at least 180 ft³/minute/ft² as measuredaccording to the procedure of ASTM D737-96 with a pressure differentialof about 0.5 inch column of water. In another embodiment, thepermeability comprises about 300 ft³/minute/ft² as measured according tothe procedure of ASTM D737-96 with a pressure differential of about 0.5inch column of water. In yet another embodiment, the reinforcingstructure comprises a permeability of more than 350 ft³/minute/ft² asmeasured according to the procedure of ASTM D737-96 with a pressuredifferential of about 0.5 inch column of water.

[0020] In one embodiment, the reinforcing structure comprises a circularbending stiffness of at least about 4 Newtons as measured according tothe procedure of ASTM D4032-94. In another embodiment, the reinforcingstructure comprises a circular bending stiffness in a range of about 4Newtons to about 15 Newtons as measured according to the procedure ofASTM D4032-94.

[0021] In one embodiment, the reinforcing structure comprises athickness of about 0.004 inches to about 0.020 inches, and typicallyabout 0.010 inches to about 0.012 inches. The reinforcement structurepreferably comprises a tensile strength in the transverse direction ofabout 200 lbs/inch as measured using the procedure of ASTM D76-99. Thereinforcement structure comprises a tensile strength in the pulldirection of at least 6 lbs/inch as measured using the procedure of ASTMD76-99.

[0022] The first reinforcing fibers comprise glass fibers, naturalfibers, carbon fibers, metal fibers, ceramic fibers, synthetic orpolymeric fibers, composite fibers (including one or more components ofglass, natural materials, metal, ceramic, carbon, and/or syntheticscomponents), or a combination thereof. In another embodiment, the firstreinforcing fibers comprise at least one polymeric component. The firstreinforcing fibers optionally comprise a surface treatment including anorganosilane agent. The organosilane agent comprises one or morefamilies of a cationic amino-functional silane, Tris(2-methoxyethoxyvinylsilane), or 3-methacryloxypropyltrimethoxysilane.

[0023] In one embodiment, the transverse direction comprises a directionabout 90°+/−10° relative to the pull direction. In another embodiment,the transverse direction comprises a direction about 90°+/−5° relativeto the pull direction. In some embodiments, substantially all of thefirst reinforcing fibers extend continuously across a width of thereinforcing structure. The reinforcing structure can optionally includea plurality of permeable transport webs.

[0024] In one embodiment, a plurality of second reinforcing fibersextend at one or more acute angles relative to the pull direction. Inthis embodiment, the second reinforcing fibers comprise a transportcomponent. In another embodiment, a plurality of second reinforcingfibers extend at a first acute angle relative to the pull direction anda plurality of third reinforcing fibers extend at a second acute anglethat is the negative of the first acute angle. A plurality of fourthreinforcing fibers extending in the pull direction can optionally beadded. In one embodiment, the first reinforcing fibers are locatedbetween the second and third reinforcing fibers.

[0025] In another embodiment, the reinforcing structure comprises aplurality of second reinforcing fibers extending at a first acute anglerelative to the pull direction, a plurality of third reinforcing fibersextending at a second acute angle that is the negative of the firstacute angle, and a plurality of fourth reinforcing fibers extendinggenerally in the pull direction. In one embodiment, the permeabletransport web comprises a plurality of fibers at least a portion ofwhich are randomly entangled with one or more of the first, second,third or fourth reinforcing fibers. In another embodiment, the permeabletransport web comprises a plurality of fibers at least a portion ofwhich are thermally bonded with one or more of the first, second, thirdor fourth reinforcing fibers. In yet another embodiment, the firstreinforcing fibers are stitched with one or more of the permeabletransport web, the second reinforcing fibers, the third reinforcingfibers, and the fourth reinforcing fibers.

[0026] In one embodiment, a binder is used to attach the permeabletransport web to one or more of the first, second, third or fourthreinforcing fibers. One or more of the first, second, third or fourthreinforcing fibers optionally comprise a polymeric component. The firstreinforcing fibers can be located between the second and thirdreinforcing fibers and the fourth reinforcing fibers. The first, second,third or fourth reinforcing fibers typically comprise discrete layers.

[0027] In another embodiment, the method comprises arranging a pluralityof first reinforcing fibers generally in a transverse direction;preparing a permeably reinforcing sheet comprising a plurality of firstpolymeric fibers comprising a first glass transition temperature and aplurality of bi-component fiber wherein a first component comprises thefirst glass transition temperature and a second component comprises asecond glass transition temperature less than the first glass transitiontemperature; and attaching a permeable transport web to the firstreinforcing fibers.

[0028] In yet another embodiment, the method comprises arranging aplurality of first reinforcing fibers in a transverse direction relativeto the pull direction and thermally bonding a permeably reinforcingsheet to the first reinforcing fibers. The reinforcing structurecomprises a permeability of at least 180 ft³/minute/ft² as measuredaccording to the procedure of ASTM D737-96 with a pressure differentialof about 0.5 inch column of water.

[0029] In yet another embodiment, the method comprises arranging aplurality of first reinforcing fibers oriented in a transverse directionand attaching a permeable transport web of staple fibers to the firstreinforcing fibers such that a ratio of a modulus of elasticity of thereinforcing structure in the transverse direction relative to a modulusof elasticity in the pull direction comprises at least 1.2. In anotherembodiment, the ratio of the modulus of elasticity of the reinforcingstructure in the transverse direction relative to the modulus ofelasticity in the pull direction comprises at least 1.5, preferably atleast 3 and more preferably at least 5.

[0030] In yet another embodiment, the method comprises arranging aplurality of non-overlapping first reinforcing fibers in a transversedirection and attaching a permeable transport web of staple fibers tothe first reinforcing fibers such that the portion of the firstreinforcing fibers extending in a transverse direction comprises atleast 30% of a volume of materials comprising the reinforcing structure.

[0031] In yet anther embodiment, the method comprises arranging aplurality of first reinforcing fibers at 45° (+/−15°) relative to thepull direction; arranging a plurality of second reinforcing fibers at−45° (+/−15°) relative to the pull direction; and attaching a permeabletransport web of staple fibers attached to the first and secondreinforcing fibers such that the first and second reinforcing fiberscomprises at least 30% of a volume of materials comprising thereinforcing structure.

[0032] In yet another embodiment, the method comprises arranging aplurality of first reinforcing fibers at 60° (+/−15°) relative to thepull direction; arranging a plurality of second reinforcing fibers at−60° (+/−15°) relative to the pull direction; and attaching a permeabletransport web of staple fibers attached to the first and secondreinforcing fibers such that the first and second reinforcing fiberscomprises at least 30% of a volume of materials comprising thereinforcing structure.

[0033] In yet another embodiment, the method comprises arranging aplurality of first reinforcing fibers in a transverse direction andattaching a permeable transport web of staple fibers to the firstreinforcing fibers such that the portion of the first reinforcing fibersoriented in the direction transverse comprises at least 40% of a volumeof materials comprising the reinforcing structure.

[0034] In yet another embodiment, the method comprises arranging aplurality of first reinforcing fibers in a transverse directioncontinuously across a width of the reinforcing structure and attaching apermeable transport web of staple fibers to the first reinforcingfibers.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0035] The invention will now be described in conjunction with theaccompanying drawings in which:

[0036]FIG. 1 is a schematic, cross-sectional view of a pultruded part inaccordance with the present invention.

[0037]FIG. 1 A is an enlarged a portion of the pultruded part shown inFIG. 1.

[0038]FIG. 2 is a further enlarged schematic detail of the pultrudedpart shown in FIGS. 1 and 1A.

[0039]FIG. 2A is a schematic illustration of an alternate pultruded partin accordance with the present invention.

[0040]FIG. 3 is a schematic illustration of a pultrusion process andequipment for carrying out a method of the present invention.

[0041]FIG. 4 is a schematic illustration of a bottom view of areinforcing mat in accordance with the present invention.

[0042]FIG. 5 is a cross-sectional view of the reinforcing mat of FIG. 4.

[0043]FIG. 6 is a schematic illustration of a top view of an alternatereinforcing mat in accordance with the present invention.

[0044]FIG. 7 is a cross-sectional view of the reinforcing mat of FIG. 6.

[0045]FIG. 8 is another cross-sectional view of the reinforcing mat ofFIG. 6.

[0046]FIG. 9 is a schematic illustration of a method of making areinforcing mat in accordance with the present invention.

[0047]FIG. 10 is a schematic illustration of an entangling device inaccordance with the present invention.

[0048]FIG. 11 is a schematic illustration of a top view of a websuitable for making a reinforcing mat in accordance with the presentinvention.

[0049]FIG. 12 is a transverse cross-sectional view of the web of FIG.11.

[0050]FIG. 13 is a longitudinal cross-sectional view of the web of FIG.11.

[0051]FIG. 14 is another cross-sectional view of the reinforcing matmade from the web of FIG. 11.

[0052]FIG. 15 is a schematic illustration of a top view of an alternatereinforcing mat in accordance with the present invention.

[0053]FIG. 16 is a cross-sectional view of the reinforcing mat of FIG.15.

[0054]FIG. 17 is an enlarged, fragmentary, schematic representation of aneedle apparatus for forming holes through the thickness of areinforcing mat.

[0055]FIG. 18 is an enlarged, fragmentary view of a representativeneedle useful for entangling staple fibers or cut fibers in areinforcing mat of the present invention.

[0056]FIG. 19 is a schematic illustration of a top view of an alternatereinforcing mat in accordance with the present invention.

[0057]FIG. 20 is a cross-sectional view of the reinforcing mat of FIG.19.

[0058]FIG. 21 is a schematic illustration of a top view of an alternatereinforcing mat in accordance with the present invention.

[0059]FIG. 22 is a cross-sectional view of the reinforcing mat of FIG.21.

[0060]FIG. 23 is a schematic illustration of a top view of an alternatereinforcing mat in accordance with the present invention.

[0061]FIG. 24 is a cross-sectional view of the reinforcing mat of FIG.23.

[0062]FIG. 25 is a schematic illustration of a top view of an alternatereinforcing mat in accordance with the present invention.

[0063]FIG. 26 is a cross-sectional view of the reinforcing mat of FIG.25.

[0064]FIG. 27 is a schematic illustration of a top view of an alternatereinforcing mat in accordance with the present invention.

[0065]FIG. 28 is a cross-sectional view of the reinforcing mat of FIG.25.

DETAILED DESCRIPTION OF THE INVENTION

[0066]FIGS. 1 and 1A illustrate a pultruded part 10 for a fenestrationproduct in accordance with the present invention. The part 10 is shownas a hollow, closed, pultruded body 12 having uniformly spaced outerwall structure 14, an inner wall structure 16 and a resin matrix 20. Thereinforcing mat of the present invention is typically located at or nearwall structures 14 and 16 to increase transverse strength, althoughother configurations are possible (see FIG. 2A). In the embodiment ofFIGS. 1 and 1A, the pultruded part 10 is a window sash rail, althoughnumerous fenestration and non-fenstration products can be made using thepresent invention. As used herein, “fenestration products” refers towindows, doors, skylights, shutters, and components thereof, such as forexample window jambs, sills, heads, sash stiles, sash rails, doorthresholds, and the like.

[0067]FIG. 2 illustrates a portion of the pultruded part 10 and areinforcing mat 18. Pultruded body 12 has wall structures 14 and 16 eachincluding the reinforcing mat 18 located on opposite sides of the resinmatrix 20. The resin matrix 20 includes longitudinally extendingreinforcing fibers, referred to herein as longitudinal rovings 22. Therovings 22 function to give the pultruded part 10 longitudinal strengthand modulus. A reinforcing mat 18 provides the pultrusion walls 14 and16 transverse strength to resist transverse forces “F” by locatingtransverse oriented reinforcing fibers in the part. The resin matrix 20preferably surrounds and impregnates the longitudinal rovings 22 and thereinforcing mat 18. A relatively thin layer 24 of the resin 20 coversthe outer face of each of the reinforcement mats 18 to provide thedesired surface characteristics. The resin matrix 20 preferablyimpregnates the reinforcing mat 18.

[0068]FIG. 2A illustrates an alternate wall structures 14A and 16A for apultruded part 10A in accordance with the present invention. Areinforcing mat 19A is located near the interior, rather than near thesurfaces. In the illustrated embodiment, one or more layers of rovings22A are positioned on both sides of reinforcing mats 18A and 19A. Thepultruded part 10A exhibits alternating layers of reinforcing mats 18A,19A and rovings 22A. A thin layer 24A of resin forms the surface of thewall structures 14A and 16A.

[0069] As illustrated in FIG. 2A, the layers of reinforcing mat androvings can be arranged in a variety of configurations and the presentinvention is not limited to locating the reinforcing mat on an outersurface of the pultruded part. The present reinforcing mats 18 or 18Apermit the manufacture of pultruded parts with wall thicknesses of about0.10 inches, and preferably about 0.06 inches and more preferably about0.03 inches or less.

[0070] The resin matrix 20 comprises about 20-40% of the cost of thepultruded part 10. Minimizing wall thickness minimizes resin cost. Thethin reinforcing mat 18 with high transverse strength of the presentinvention permits a reduction in wall thickness without compromisingtransverse strength.

[0071] The present reinforcing mat typically has a compressed thicknessof about 0.004 inches to about 0.020 inches. In another embodiment, thereinforcing mat has a compressed thickness of about 0.010 inches toabout 0.012 inches. Since the reinforcing mat can be made relativelythin with a low areal density and reinforcing fibers oriented in thetransverse direction, the present reinforcing mat can be used to makerelatively thin pultruded parts.

[0072] In some embodiments, pultruded parts may be manufactured usingthe thin reinforcing mats of the present invention in which the profileconsists of resin impregnated longitudinal rovings or reinforcing fiberstotaling a thickness of about 0.019 inches, with a resin impregnatedreinforcing mat layer about 0.010 inches thick on each sides of therovings, for a total wall thickness of about 0.039 inches or less. Inanother embodiment, the wall thickness is about 0.045 inches to about0.025 inches. The present reinforcing mat permits about a 33% reductionin wall thickness with the same or greater transverse strength thanpultruded parts reinforced with conventional continuous filament mats.Wall thickness of about 0.039 inches using the present reinforcing matshave demonstrated a transverse tensile strengths of about 20,000 psi.

[0073] As used herein, “reinforcing fiber” refers to a single filamentsuch as a monofilament, or a grouping of a plurality of pliable,cohesive threadlike filaments, including without limitation glassfibers, natural fibers, carbon fibers, metal fibers (such as for examplealuminum), ceramic fibers, synthetic or polymeric fibers, compositefibers (such as a polymeric matrix with a reinforcement of glass,natural materials, metal, ceramic, carbon, and/or syntheticscomponents), or a combination thereof. Although the Figures illustratethe reinforcing fibers schematically as a single entity or structure,each discrete reinforcing fiber illustrated herein can be interpreted aseither a single filament, such as a monofilament, or a group offilaments. As used herein, “roving” refers to a plurality of reinforcingfibers. Rovings are typically not twisted or kinked so that maximumlongitudinal strength is maintained.

[0074]FIG. 3 schematically illustrates a pultrusion system 111 suitablefor use with a reinforcing mat in accordance with the present invention.One or more reinforcing mats 18′, 18″ (referred to collectively as “18”)are directed from source rolls 116, 140, respectively over illustratedrollers 118 and/or 120 to resin bath 122. The wetted reinforcing webs 18pass over roller 124 into the pultrusion die 54. A plurality oflongitudinal rovings 126 from source roll 128 passes over roller 130,through resin bath 132, and then over rollers 134, 136 and 138 into thedie 54. The pultrusion die 54 typically has a profile corresponding toor otherwise needed to form the cross-sectional shape of the pultrudedpart 12. The longitudinal fibers are typically 675-yield (about 675yards per pound), 450-yield, 250-yield, or 113-yield glass reinforcingfibers, although fibers with other yields or non-glass fibers can beused for some applications.

[0075] A variety of techniques well known to one skilled in the art suchas carding plates can be used to pre-form or pre-shape the rovings andthe reinforcing mats 18 for pulling through the die 54. The reinforcingmats described herein can be used in pultrusion processes using the sametechniques as are used for conventional mats. The rovings and thereinforcing mats are collated together for passage through the die butare generally not connected until unified by the setting resin. Inanother embodiment, the reinforcing mats 18 are attached to some of thelongitudinal rovings 126, such as by stitching, adhesives and otherattaching techniques. In yet another embodiment, the reinforcing mats 18can be trapped between layers of rovings, such as illustrated in FIG.2A. As the longitudinal rovings 126 are pulled through the die 54, themats 18 are pulled along. The reinforcing mat 18 can be shaped using thesame mechanisms used to position the longitudinal rovings 126 relativeto the die 54.

[0076] Prior to entering the die, the reinforcing mats 18 are preferablyshaped to correspond generally with the profile of the die 54. Rollforming analogous to those used in forming sheet metal and/orheat-setting techniques can be used to shape the reinforcing mats 18.Other suitable methods for shaping the mats 18 are disclosed in U.S.Pat. Nos. 4,752,5134 (Rau et al.) and 5,055,242 (Vane).

[0077] Pulling mechanism 52, which for example may comprise a pair ofopposing rollers, is operable to pull part 12 from a pultrusion die 54.Instead of passing the longitudinal rovings 126 and the reinforcing mats18 through respective resin baths 122, 132, as shown schematically inFIG. 3, resin may be applied to the reinforcing fiber and thereinforcing mats 18 using conventional resin-applying procedures thatare well known to those skilled in this art. Various techniques formaking pultruded parts are disclosed in U.S. Pat. Nos. 4,564,540 (Davieset al.); 4,752,513 (Rau et al.); 5,322,582 (Davies et al.); and5,324,377 (Davies).

[0078] The positioning of the longitudinal rovings 126 and thereinforcing mats 18 relative to the die 54 in FIG. 3 is purely schematicand may change depending upon the desired position of the reinforcingmats 18 and the longitudinal rovings 126. The reinforcing mats 18 andthe longitudinal rovings 126 can be located anywhere in a pultrudedpart. For example, as illustrated in FIG. 2A, alternating layers ofreinforcing mats 18A, 19A and longitudinal rovings 126 can be locatedthroughout the pultruded part 12. In some embodiments, the longitudinalrovings 126 may be closest to the surface of the part, rather than themat.

[0079] A conventional pultrusion resin formulation may be used forpultruding part 10. A typical formula may include, for example, amixture of thermoset polyester resin containing a reactive diluent suchas styrene, along with a hardener, a catalyst, inorganic fillers, asuitable surface modifier, and a die lubricant. Suitable resins aredisclosed in U.S. Pat. Nos. 4,752,513 (Rau et al.); 5,908,689 (Dana etal.); and 5,910,458 (Beer et al.). A commercially available thermosetresin suitable for use in the present invention is available from ResinSystems Incorporated located in Edmonton, Alberta under the productdesignation Version G. Other suitable suppliers may include Reichhold,Ashland, and Dow.

[0080] Thermosetting matrix materials useful in the present inventioncan include thermosetting polyesters, vinyl esters, epoxides, phenolics,aminoplasts, thermosetting polyurethanes, derivatives and mixturesthereof. Suitable thermosetting polyesters include the AROPOL productsthat are commercially available from Ashland Chemical Inc. of Columbus,Ohio. Examples of useful vinyl esters include DERAKANE.RTM. productssuch as DERAKANE.RTM. 470-45, which are commercially available from DowChemical USA of Midland, Mich. Examples of suitable commerciallyavailable epoxides are EPON.RTM. 826 and 828 epoxy resins, which areepoxy functional polyglycidyl ethers of bisphenol A prepared frombisphenol-A and epichlorohydrin and are commercially available fromShell Chemical.

[0081] Non-limiting examples of suitable phenolics includephenol-formaldehyde from Monsanto of St. Louis, Mo., cellobond phenolicfrom Borden of Columbus Ohio, and specific phenolic systems formulatedfor pultrusion from BP of Chicago Ill., Georgia Pacific of Atlanta Ga.,and Inspec (Laporte Performance Chemicals) of Mount Olive N.J. RESIMENE841 melamine formaldehyde from Monsanto. Useful aminoplasts includeurea-formaldehyde and melamine formaldehyde. Suitable thermosettingpolyurethanes include Adiprene® PPDI-based polyurethane supplied byUniroyal Chemical Company, Inc. of Middlebury, Conn. and polyurethanesthat are available from Bayer of Pittsburg, Pa., Huntsman of Edmonton,Alberta, and other resin formulators such as E. I. du Pont de NemoursCo. of Wilmington Del. Other components which can be included with thethermosetting matrix material and reinforcing mat in a pultruded partare, for example, colorants or pigments, lubricants or process aids,ultraviolet light (UV) stabilizers, antioxidants, other fillers, andextenders.

[0082] The resin used in producing the pultrusion product can be filledwith other materials, either at the longitudinal reinforcing fiber area,at the surface mat areas, or both. Fillers are generally present inamounts ranging from a trace amount to 30 percent, preferably 10 to 25percent and most preferably 15 percent. The fillers may be any suitablefiller utilized by the art to fill a resin system of the type beingproduced. Fillers and pigments such as calcium carbonate, titaniumdioxide, hydrated alumina, kaolin clay, silicon dioxide, carbon blackand the like may be used. Wood flour, recycled plastic grinds, metalgrinds such as Valimet H2 spherical aluminum powder or HoeganaesAncoorsteel 1000 atomized steel powder, fly ash, or the like, can alsobe used to reinforce or fill the resin of the pultruded part, to obtainimproved mechanical properties, to improve aesthetics, to increase ordecrease density, or to reduce cost. Wood-fibers may be employed toachieve a natural-wood color in the pultruded product, in addition tothe enhanced strength and lowered material cost.

[0083]FIGS. 4 and 5 illustrate one embodiment of a reinforcing mat 18Ain accordance with this invention. The reinforcing mat 18A includes aseries of separate, transversely spaced, reinforcing fibers 28 (alsoreferred to as transport fibers) comprising a first longitudinal layer30. In the illustrated embodiment, the first layer 30 is made up ofrelatively fine reinforcing fibers 28 extending longitudinally in the 0°or pull direction 29 of reinforcing mat 18A. These reinforcing fibers 28can be oriented in the range of 0° to about +/−20°, and preferably about+/−10°, and more preferably +/−5°. As used herein, the term “layer”refers to the schematic illustration of the various reinforcing fibersin the Figures and is not intended to limit the structure of the presentreinforcing mat.

[0084] A second set of spaced reinforcing fibers 32 comprising atransverse second layer 34 extend at an angle of about 90° with respectto the pull direction 29. Reinforcing fibers 32 are desirably positionedin substantially directly side-by-side, non-overlapping, slightly spacedrelationship to form a blanket of fibers without substantial breakstherebetween. As used herein, “non-overlapping” refers to generallycoplanar fibers that do not extend over or cover one another. Each ofthe reinforcing fibers 32 preferably extend continuously across thewidth of reinforcing mat 18A from edge portion 43 to edge portion 45. Asused herein, “extend continuously” refers to a single strand ofreinforcing fiber running in an unbroken segment from one edge of areinforcing mat to another edge. The 90° orientation of the reinforcingfibers 32 maximizes the transverse strength and increased modulus of thepultruded part 10. In lieu of the preferred 90° orientation, thereinforcing fibers 32 may be positioned at other angularities within therange of about 90°+/−30° and more typically about 90°+/−20° (relative tothe 0° or pull direction 29) in the plane of the mat

[0085] In the illustrated embodiment, the reinforcing fibers 32 have asubstantially larger cross-sectional profile than the cross-sectionalprofile of each of the elongated reinforcing fibers 28, as is evidentfrom the schematic representations of FIGS. 4 and 5. In an embodimentwhere the transverse reinforcement fibers 32 extending in the 90°direction (+/−30°) are not overlapping (see e.g., FIGS. 4 and 5), theypreferably comprise at least 30%, and more preferably at least 40%, ofthe total volume of material comprising the reinforcing mat 18A. In anembodiment where the first reinforcing fibers 32 are overlapping (seee.g., FIGS. 27 and 28), the reinforcing fibers extending in the 90°direction (+/−30°) direction preferably comprise at least 40%, and morepreferably at least 50%, of the total volume of material comprising thereinforcing mat 18A. As used herein, the pull direction 29 is designated0°. The orientation of all other reinforcing fibers will be referencedfrom the pull direction 29. The pull direction 29, however, isindependent of the orientation of any particular reinforcing fiber. Thereinforcing mat 18 can be oriented in any direction for pulling throughthe pultrusion die, although some directions are preferred over other.For most applications, however, the larger reinforcing fibers 32 arepreferably oriented transverse from the pull direction 29. As usedherein, “transverse” refers to a direction generally perpendicular tothe 0° or longitudinal pull direction +/−30°, and typically +/−20°, in aplane of a reinforcing mat.

[0086] Angular reinforcing fibers 38 comprising an angular reinforcinglayer 36 extend at an angle of about 45° with respect to the pulldirection 29. In the illustrated embodiment, the reinforcing layer 36 islocated adjacent to the layer 34. The reinforcing fibers 38 shown inFIGS. 4 and 5 have a smaller cross-sectional area as compared with thecross-sectional area of transverse reinforcing fibers 32.

[0087] Another angular reinforcing layer 40 is located adjacent to thelayer 36. The reinforcing fibers 42 are desirably at angle of about 45°with respect to the 0° or the pull direction 29. The angularity ofreinforcing fibers 38 may be characterized as +45° while the angularityof reinforcing fibers 42 may be characterized as −45° both with respectto the 0° or the pull direction 29. The reinforcing fibers 38 and 42 ofangular layers 36 and 40 may be positioned in diagonal directions withinthe range of about +30° to about +60° and from about −30° to about −60°,respectively. The angular reinforcing fibers 38 and 42 operate, at leastin part, as transport fibers that provide longitudinal strength, shearstrength and skew resistance. As used herein, “transport fiber” refer tofibers that assist in maintaining the integrity of the reinforcing matas it is drawn through the pultrusion die.

[0088] The reinforcing fibers 38 of layer 36 and reinforcing fibers 40of layer 42, extending in opposite directions at 45° angles impart shearstrength to the reinforcing mat 18A. This increased shear strength isattributable to the fact that reinforcing fibers 38 of layer 36 andreinforcing fibers 42 of layer 40 transmit forces substantially equallyin the opposite directions to edge portions 43 and 45 of the mat. Byproviding such diagonally and oppositely oriented fibers at +45° and−45°, there is minimal tendency for one of the edge portions 43 or 45 tomove in advance of the other edge and thus a twisting or skewing thereinforcing mat during pultrusion of part 10. As used herein, “skew”refers to a change in the angular relationship of reinforcing fibers inthe plane of a reinforcing mat. Skew typically is exhibited by one sideedge of the reinforcing mat moving in advance of the other side edgeduring pultrusion.

[0089] The reinforcing fibers 38 and 42 are preferably continuous andextend across the width of the reinforcing mat so as to maximizetransmission of forces in respective diagonal directions. The volume ofreinforcing fibers in the layer 36 is preferably about the same as inthe layer 40 so that there is a generally uniform resistance to skewingand shear strength stiffness modulus throughout the reinforcing mat 18A.Layer 30, in conjunction with layers 36 and 40, gives the reinforcingmat 18A dimensional stability in the 0° and +/−45° directions so thatthe reinforcing mat 18A can be bent to make pultruded parts with complexshapes, yet offer sufficient tracking consistency and necking-resistancefor consistent processing during pultrusion.

[0090] A permeable transport layer 44 is located adjacent to the layer40, although one or more reinforcing layers 44 can be located betweenany of the layers 30, 34, 36, 40 of FIG. 5. In the illustratedembodiment, the permeable transport layer 44 comprises a permeabletransport web comprising a plurality of relatively short staple fibersor cut fibers 46. The permeable transport layer 44 is preferably made upof randomly oriented staple or cut fibers of a length within the rangeof about 0.01 to about 12″, and preferably in the range of about ½″ toabout 4″. The staple fibers are preferably heat-fusible fibers. As usedherein, “permeable transport web” refer to a plurality of staple fibersattachable to various reinforcing fibers in a reinforcing mat to providelongitudinal strength, shear strength and anti-skew properties. Prior toattachment to the reinforcing fibers, the staple fibers can be acollection of loosely associated fibers, a batting material, or avariety of other configurations. As will be discussed in detail below,in some embodiments the permeable transport web operates in combinationwith other transport components, such as binders, stitching fibers,adhesives, thermal bonding, various methods for entangling the staplefibers with the reinforcing fibers, diagonal reinforcing fibers (alsoreferred to as transport fibers), and the like.

[0091] A proportion of fibers 46a are deflected from the plane of thelayer 44 to become randomly oriented, intertwined and entangled with thereinforcing fibers 28, 32, 38, 42. The staple fibers or cut fibers 46 aeffectively mechanically interconnect or attach the layers 30, 34, 36,40 and 44. The entangling fibers 46 a preferably extend substantiallythrough the thickness of reinforcing mat 18A and prevent the layers 30,34, 36, 40 and 44 from separating or moving one with respect to anotheras the reinforcing mat 18A is pulled through a pultrusion die 54. Thereinforcing layer 44 also maintains the relative position of therespective fibers 28, 32, 38, 42 in the reinforcing mat 18A.

[0092] In addition to interconnecting the layers 30, 34, 36, 40 and 44,the layer 44 provides strength and resistance to skew in substantiallyall directions. Additionally, while the layer 30 provides strengthprimarily in about the 0° or pull direction 29, the fibers 28 willresist skewing forces at some angles other than 0°. Similarly, thefibers 32 will resist skewing forces at some angles other than 90° andthe fibers 38, 42 will resist skewing forces at angles other than+/−45°. It is the combined effect of the reinforcing layer 44 and thevarious fiber layers 30, 34,36, 40 that provide the present reinforcingmat 18 with the properties that make it suitable for pultrusion.

[0093] The contributions of the fibers 28 and 42 in combination with thereinforcing layer 44 provides the reinforcing mat 18A with sufficientin-plane mechanical stability so that thin walled pultruded parts can bemade with minimal skewing of the reinforcing mat 18 and minimal shiftingof the relative position of fibers 28, 32, 38, 42. For a planarreinforcing structure, the phrase “in-plane mechanical stability” refersto a resistance to deformation and skew in the plane of the articlesufficient to use in a pultruded part having a non-planar profile.

[0094] In another embodiment, the layers 30, 34, 36, 40 and 44 can beinterconnected or attached by stitching with a fiber 47 using aconventional multi-head stitching machine used in the textile industry.It can be seen in FIGS. 4 and 5 that the fiber 47 pass through andinterconnect all of the layers 30, 34, 36 and 40 of reinforcing mat 18A.In another embodiment, the layer 44 can also be stitched to the otherlayers 30, 34, 36 and 40. In yet another embodiment, the firstreinforcing fibers 32 can be spaced apart and attached together bycontinuous fiber stitching 47.

[0095] In the embodiment illustrated in FIG. 5, the stitching fiber 47wraps around some of the reinforcing fibers 32. In embodiments where thereinforcing fibers 32 are groupings of filaments, the stitching fiber 47can pass between individual filaments in the reinforcing fibers 32 (seee.g., FIG. 20).

[0096] The fiber 47 illustrated in FIGS. 4 and 5 are schematic only. Byvirtue of the flexibility of the individual stitches interconnectinglayers 30, 34, 36 and 40, the reinforcing mat remains highly flexible,although mechanically interconnected in a stabilized manner by the fiber47. The fiber 47 can be polyester thread, a natural fiber thread as forexample cotton, or a variety of other known materials.

[0097] In another embodiment, the layers 30, 34, 36, 40 and 44 may beinterconnected or attached using a variety of other techniques. As usedherein, “attach” refers to mechanical and or chemical techniques,including without limitation stitching, entangling strands of staplefibers or cut fibers intimately with the reinforcing fibers, thermalbonding, ultrasonic welding, adhesive bonding, conductive andnon-conductive binders, mechanical entanglement, hydraulic entanglement,vacuum compaction, or combinations thereof. Adhesive bonding includespressure sensitive adhesives, thermosetting or thermoplastic adhesives,radiation cured adhesives, adhesives activated by solvents, andcombinations thereof. Binders may also include a thermoplastic resinsheathing on certain or all of the reinforcing fibers, or such resinsheathing may if desired take the place of an added thermoplasticbinder. Suitable binders are disclosed in U.S. Pat. Nos. 4,752,513 (Rauet al.); 5,908,689 (Dana et al.); and 5,910,458 (Beer et al.).

[0098] The present reinforcing mat 18A has a modulus of elasticity inthe transverse or 90° direction that is greater than the modulus ofelasticity in the 0° or pull direction. The ratio of the modulus ofelasticity in the transverse direction to the modulus of elasticity inthe 0° or pull direction is preferably at least 1.2, more preferably1.5, and still more preferably 3. In some embodiments the ratio is atleast 5. As used herein, “modulus of elasticity” refers to a ratio ofthe increment of some specified form of stress to some specified form ofstrain, such as Young's modulus, the bulk modulus, or the shear modulus.Modulus of elasticity can also be referred to as the coefficient ofelasticity, the elasticity modulus, or the elastic modulus. Modulus ofelasticity can be evaluated using ASTM D76-99 (Standard Specificationfor Tensile testing Machines for Textiles).

[0099] The present reinforcing mat can also be used for all othercomposite processes, and is especially capable of high-strength, due tothe oriented fibers, or reduced thickness, to decrease part cost orweight. The reinforcing mat can be used in composite spray-up parts,filament wound parts, resin-transfer-molded parts,structural-reaction-injection molded parts, sheet-molding-compoundparts, vacuum-bag parts, and other composite assemblies, to achieve athin wall, low cost, low weight, high strength, or the like. The processof using this reinforcing mat would be similar to the currenttechnologies of process, but thinner parts, or multiple-mat thicknessparts would be produced, as could be understood by those skilled inthese arts.

[0100] FIGS. 6-8 illustrate an alternate reinforcing mat 18B inaccordance with the present invention. The reinforcing mat 18B has a 0°layer 30′ made up of a series of longitudinally extending reinforcingfibers 28′. The layer 30′ is adjacent to transverse layer 34′ made up ofa series of side-by-side reinforcing fibers 32′. Angular fiber layers36′ and 40′ made up of reinforcing fibers 38′ and 42′, respectively, arelocated on opposite faces of the 0° reinforcing fiber layer 30′ and 90°transverse reinforcing fiber layer 34′, respectively, as best shown inFIGS. 6 and 7. The diagonally oriented reinforcing fibers 42 and 38 mayhave an angularity of about +/−45° to angles within the range of about+/−30° to about +/−60°. Permeable transport layer 44′ is positioned inoverlying relationship to the outer face of angular reinforcing fiberlayer 36′. The layer 44′ comprises a series of relatively short staplefibers 46′ with the entangled connecting fibers being designated by thenumeral 46 a′.

[0101] FIGS. 11-13 illustrate a precursor web before the addition of apermeable transport layer. Two longitudinally extending reinforcinglayers 144 and 146 are provided on opposite sides of centrally located,substantially larger reinforcing fibers in transverse layer 148. Twoangular reinforcing layers 150 and 152 are positioned against the faceof longitudinal layer 144 opposite transverse layer 148. The angularreinforcing layers 150 and 152 are preferably oriented in oppositediagonal directions at about 45° with respect to the longitudinal lengthof the mat. FIG. 14 illustrates a reinforcing mat 18C made from theprecursor structure of FIG. 13. A permeable transport layer 154 ispositioned on top of the diagonal reinforcing fiber layer 150. Therelatively short fibers of the permeable transport layer 154 areschematically shown as being entangled with the layers 144, 146, 148,150, 152.

[0102] FIGS. 15-16 illustrate a reinforcing mat 18D in which diagonalreinforcing fibers 160 and 162 are positioned at 70° angles with respect0° or the pull direction 29. The layers 164 and 166 are located onopposite sides of the layer 168 containing the transverse reinforcingfibers 170. The permeable transport layer 172 interconnects or attachesthe layers 164, 166, 168, and 172. The diagonal reinforcing fibers 160,162 provide adequate dimensional stability in the pull direction 29 sothat the 0° reinforcing fibers can be omitted.

[0103] FIGS. 19-20 illustrate another embodiment of a reinforcing mat18E in accordance with the present invention. The reinforcing mat 18Eincludes a series of elongated, separate, essentially parallel, spaced,transverse reinforcing fibers 220 arranged to form a transversereinforcing layer 222. The reinforcing fibers 220 of reinforcing layer222 are oriented at an angle of approximately 90° with respect to 0° orthe pull direction 29 of a part through the die 54. The reinforcingfibers 220 are laid continuously across with width of the reinforcingmat 18E and lie in a slightly spaced, side-by-side relationship. Aspreviously explained, transversely oriented reinforcing fibers increasethe modulus of a pultruded part 10 reinforced with reinforcing mat 18E.Although reinforcing fibers 220 illustrated at 90° in FIG. 19, thereinforcing fibers 220 may be positioned at other angularities withinthe range from about 60° to about 120° in the plane of the mat. Also aspreviously indicated, transverse fiber reinforcing fibers 220 normallyare present in an amount within the range of about 40% to about 90% ofthe total volume of material comprising the reinforcing mat 18E.

[0104] Mat 18E also has two layers 224, 226 of angled reinforcing fibers228, 230, respectively. As is most evident from FIG. 19, the reinforcingfibers 228 of layer 224 are at an angle of about +45° with respect to 0°while the reinforcing fibers 230 of layer 226 are at an angle of about−45°. The reinforcing fibers 228, 230 of layers 224, 226 are of a lesserdiameter than the diameter of individual transverse reinforcing fibers220 in order to maintain the as much of the volume of the reinforcingmat 18E in the transverse or 90° direction.

[0105] The layers 224, 226, 228 are interconnected or attached byspaced, parallel individual lines of stitching 232. In the embodiment ofFIG. 19, the reinforcing fibers 220 are typically groups of filamentsthrough which the stitching 232 can pass. From FIG. 19 it can be seenthat the lines of stitching 232 extend in perpendicular relationship toreinforcing fibers 220. Each line of stitching 232 is made up of arelatively straight bobbin thread 234 and a serpentine stitch thread236. The bobbin thread 234 of each line of stitching 232 generally laysin underlying relationship to the reinforcing fibers 220, while thestitch thread 236 of each line of stitching 232 extends into overlyingrelationship to the layer 224 of reinforcing mat 18E, thus serving tointerconnect layers 222, 224, 226. As used herein, a “stitched thread”is located on a front surface of a reinforcing mat and a “bobbin thread”is located on the opposite side of the mat.

[0106] It is also to be observed from FIG. 19 that the upper rightsegments 236 of adjacent stitch threads 236 are offset from one anotherin a direction perpendicular to reinforcing fibers 220. The lines ofstitching are applied using a multiplicity of adjacent, mutuallycooperative, individual stitching heads as previously herein. Althoughpolyester thread is preferred for lines of stitching 232, other commonmaterials may be used such as cotton thread or other natural orsynthetic resin fibers, depending upon the pultrusion process, themechanical properties desired of for example a pultruded fenestrationproduct, or other pultruded part.

[0107] A permeable transport layer 238 is provided in overlyingrelationship to layer 224. The permeable layer 238 is preferably made upof randomly oriented staple fibers. At least a certain proportion of thestaple fibers are entangling fibers 240 that randomly extend through atleast a part of the composite thickness of reinforcing mat 18 and serveto further interconnect the individual layers 222, 224, 226, 238 ofreinforcing mat 18 in conjunction with the lines of stitching 232.

[0108] The entangling fibers 240 are preferably hydro-entangled withlayers 222, 224, 226 utilizing hydro-entanglement equipment andemploying procedures as described herein. The closely spaced heads ofthe hydro-entangler divert staple fibers from the plane of the layer 238thereby causing hydro-jet diverted staple fibers to extend randomly in adirection through the thickness of the composite mat 18E. To that end,the staple fibers making up reinforcing mat 18E preferably have arelatively low resistance to bending so that randomly oriented fibersare forced downwardly into and through the layers of the reinforcing matbelow using hydroentangling equipment.

[0109]FIGS. 21 and 22 illustrate an alternate the reinforcing mat 18Fsimilar to that illustrated in FIGS. 19 and 20, except that the layers322, 324, 326 and 328 are attached without stitching. Transversereinforcing fibers 320 are arranged at 90° to the pull direction 29. Twoangled reinforcing layers 324, 326 of angled reinforcing fibers 332, 334oriented at about +/−45° are positioned between the layer 322 and thepermeable transport layer 328. Fibers 330 from the layer 328 extendthroughout the thickness of the reinforcing mat 18F to form a mechanicalbond between the layers 322, 324, 326, 328. Supplemental holes 336 areformed in the permeable layer 328 to facilitate wetting of thereinforcing mat 18F with resin during the pultrusion process. Secondaryattaching techniques may also be used, such as the addition of bindersand/or adhesives, thermal bonding, and the like.

[0110]FIGS. 23 and 24 illustrate an alternate reinforcing mat 18G inwhich the layer 352 of reinforcing fibers 354 arranged at 90° from thepull direction are stitching 356. The first reinforcing fibers 354 arepreferably spaced apart and attached together by continuous fiberstitching 356. The stitching 356 holds the reinforcing fibers 354 in anarray during attachment of permeable transport layer 358. The permeabletransport layer 358 is provided on at least one side of the layer 352.Staple fibers 360 of layer 358 are entangled with the reinforcing fibers354 of transverse reinforcement layer 352 to form a reinforcing mat within-plane mechanical stability. Supplemental holes 362 are formed in thepermeable layer 358 to facilitate wetting of the reinforcing mat 18Fwith resin during the pultrusion process.

[0111] In another embodiment, the array of transverse reinforcing fibers354 and the permeable transport layer 358 are stitched together to forma combined structure. The stitching is preferably applied afterhydraulic entanglement and heat fusing of the transverse reinforcingfibers 354 to the permeable transport layer 358.

[0112]FIGS. 25 and 26 illustrate an alternate reinforcing mat 18H havinga layer 402 of transverse reinforcing fibers 404 arranged at about 90°relative to the pull direction 29. A permeable transport layer 406 ispositioned on one side of the layer 402. Staple fibers 408 of the layer406 are entangled with the layer 402 to form a reinforcing mat 400 within-plane mechanical stability. Supplemental holes 410 are formed in thelayer 406 to facilitate wetting during pultrusion. In addition to theentangled staple fibers 408, other techniques disclosed herein may alsobe used to attach the layer 402 to the layer 406, such as thermal oradhesive bonding, binders, stitching and the like. In one embodiment, asecond permeable transport layer 412 is optionally located on the otherside of the layer 402. Fibers 414 from the layer 412 also entangle withfibers 408 from the layer 406. The second layer 412 reinforces thereinforcing mat 18H, particularly if the layers 406 and 412 arethermally bonded.

[0113]FIGS. 27 and 28 illustrate an alternate reinforcing mat 181 havingtwo layers 420, 422 of transverse-acting reinforcing fibers 424, 426,respectively. The transverse-acting reinforcing fibers 424, 426 have asubstantially larger cross section, corresponding generally to thetransverse reinforcing fibers 32 in FIG. 5. In one embodiment, thereinforcing fibers 424 are arranged at about 60° (+/−15°) relative tothe pull direction 29. The reinforcing fibers 424 are desirablypositioned in substantially directly side-by-side, non-overlapping,slightly spaced relationship. The reinforcing fibers 426 are arranged atabout −60° (+/−15°) relative to the pull direction 29. The reinforcingfibers 426 also do not overlap with each other. The layers 420, 422,however, do overlap. As used herein, “overlap” refers to fibers thatextend over or cover one another.

[0114] In another embodiment, the reinforcing fibers 424, 426 arearranged at 45° and −45° (+/−15°), respectively. While the orientationof the fibers 424, 426 in these two embodiments are outside thedefinition of “transverse”, arranging the reinforcing fibers 424, 426 atopposing angles in these ranges is desirable for some applications. Inboth embodiments, the reinforcing fibers 424, 426 preferably comprisesat least 30% of a volume of materials comprising the reinforcing mat181, and more preferably 40%.

[0115] A first permeable transport layer 430 is positioned on one sideof the layers 420, 422. Staple fibers 432 of the layer 430 are entangledwith the layers 420, 422 to form a reinforcing mat 181 with in-planemechanical stability. Supplemental holes 434 are formed in the layer 430to facilitate wetting during pultrusion. In one embodiment, a secondpermeable transport layer 436 is optionally located on the other side ofthe layers 420, 422. Fibers 432 from the layer 436 also entangle withfibers 424, 426. The second layer 436 reinforces the reinforcing mat181, particularly if the layers 430,426 are thermally bonded. In anotherembodiment, an additional layer of reinforcing fibers is provided in the0° direction to enhance pulling strength (see FIG. 4).

[0116] Method of Making a Reinforcing Mat

[0117]FIG. 9 illustrates an apparatus 78 for making the reinforcing mat18 in accordance with the present invention. The apparatus 78 includes aconveyor belt 80 arranged to carry the components of the reinforcing mat18 from an initial supply to a wind-up device 82. The longitudinallength 84 of the belt corresponds to the 0° direction of the reinforcingmat 18 during manufacturing.

[0118] A precursor web 85 is made by sequentially laying onto the belt80 a plurality of reinforcing fibers from supply units 86, 88, 90, and92. A plurality of needles are preferably located along the edges of thebelt 80. Supply head 90 continuously lays down reinforcing fibers alongthe longitudinal length of belt 80, thus providing a 0° lay ofreinforcing fibers. Reinforcing fibers supply head 88 is operable toreciprocate back and forth across the width of belt 80 to lay down 90°transverse reinforcing fibers. The reinforcing fibers are wound aroundneedles along each edge of the endless belt 80 to arrange thereinforcing fibers for the desired orientations.

[0119] Angled reinforcing fiber supply head 92 lays down a reinforcingfibers on the previously applied 0° and 90° reinforcing fibers at abouta 45° angle. Diagonal reinforcing fiber supply head 86 functions to laydown reinforcing fibers at an angle of about −45° with respect to thelongitudinal length 84 of the belt 80. The head 86 traverses back andforth across belt 80 in timed relationship to the speed of the belt 80to provide angled reinforcing fibers. The angled reinforcing fibers arewound around the needles along each edge of the endless belt 80.Preferred results have been obtained by using 11 courses per inch of 90°reinforcing fiber, about 8 courses per inch of 45° angular reinforcingfibers, and about 8 courses per inch of 0° reinforcing fibers in anassembled web 18.

[0120] The present method permits the combination of 0°, 90° and +/−45°reinforcing fibers to be varied. For example, the 0° fibers can beeliminated to make a reinforcing mat similar to that illustrated inFIGS. 15 and 16. In another embodiment, only the 90° reinforcing fibersare applied, such as illustrated in FIGS. 25 and 26. Various methods fordepositing the layers of reinforcing fibers are disclosed in U.S. Pat.Nos. 4,484,459 (Hutson); 4,550,045 (Hutson); 4,677,831 (Wunner); and5,308,424 (Sasaki et al.).

[0121] In one embodiment, a plurality of stitching heads 94 are provideddown stream of the supply units 86, 88, 90, 92. The stitching heads 94optionally form spaced, parallel lines of stitching in the layers ofreinforcing fibers (see e.g., FIG. 20). The stitch thread can bepolyester, aramid thread for toughness, natural fibers for cost,polyamides, such as Pegaso Micro Helanfil 2×80 dtex or HoneywellAnso-tex nylon, for resilience, or carbon threads for stiffness orhigh-temperature capability. A suitable assembly for depositing thelayers of reinforcing fibers and stitching the layers together isavailable from LIBA Maschinenfabrik GmbH of Germany under the tradedesignation Centra Max 3 CNC fiber inserter.

[0122] In another embodiment, the stitching is omitted and the web 85 ispassed under a hot roll 98 to assist in bonding of the layers of the web85 one to another. The use of hot roll 98 is particularly suited whenone or more of the reinforcing fibers contain a polymeric component. Theroll 98 act also to calender the web 85 so that it is compressed andslightly reduced in thickness. The temperature of the roll 98 ispreferably selected to cause the minimal amount of softening of thepolymeric content and still achieve an adequate bond between the fibers.The roll 98 may also bond the polymeric components of the reinforcingfibers by imparting ultrasonic energy. In another embodiment, the heatis omitted and a simple calendering action is used.

[0123] Non-woven machine 100 deposits polymeric cut-staple fibers ontothe web 85. The non-woven machine 100 can be a variety of structures,such as for example an air lay machine or a mechanical card. The staplefibers are the precursor material for making the permeable transportlayer discussed herein. The staple fibers are typically blended andcarded, and a predetermined thickness is achieved by stacking aplurality of layers of staple-fiber webs or batting onto the web 85.

[0124] In one embodiment, the staple fibers comprise a non-woven battingweb may be made by blending of polyester staple fibers. The staplefibers preferably include a portion of high melt fibers and a portion oflow melt fibers. In another embodiment, the low melt fibers are abi-component fiber with a high melt portion and a low melt portion. Thelow melt portion provides a bonding function with the various layers,while the high melt portion minimizes warping and shrinkage of thereinforcing mat 18 and excessive flow of the low melt polymer. Apreferred bi-component fiber is a core-sheath configuration with the lowmelt polymer on the sheath and the high melt polymer at the core. In oneembodiment, the high melt fibers have a glass transition temperature ofabout 350° F. and the low melt fibers have a glass transitiontemperature of about 270° F.

[0125] In another embodiment, the non-woven machine 100 may includespinning needles that convert an open fiber polymeric material into highloft “tufts” of non-woven fibers. The tufts of high loft material aredeposited in an accumulator until a target weight is reached, whereuponthe tufts are dropped onto the web 85. When more than one type of openfiber polymeric material is used, separate accumulators are used so thatthe percentage of each type of material can be independently controlled.

[0126] In one embodiment, the staple fibers are blended and opened in anon-woven opener sold under the product referred to as a carding machineor garnet wheel sold by Sigma Fiber Controls of Simpsonville, S.C. Thestaple fibers and/or cut fibers are then fed through a Rando webber sothat a density of about 32 gram/meter² to about 60 gram/meter² isreached. The Rando feed and doff speeds are set to achieve the desireddensity. One or more layers of the non-woven batting is then depositedon the web 85.

[0127] After the staple fibers are laid onto the web 85, they areentangled with the layers of reinforcing fibers. In the illustratedembodiment, the staple fibers are entangled using a water-jethydro-entangler 66, such as the structure illustrated in FIG. 10. Thehydro-entangler 66 substantially compresses the staple fibers to achievethe overall reinforcing mat thickness of about 0.004 inches to about0.020 inches. The individual jets of water wet the randomly orientedfibers of the staple fibers directly to the reinforcing fibers and forcecertain of the fibers into locations extending throughout thereinforcing mat 18. In some circumstances the water jets from thehydro-entangler unit may break up some of the fibers of the reinforcingfibers to produce shorten tangling fibers randomly oriented in the samemanner as entangling staple fibers. These broken reinforcing fibers mayextend throughout the cross-section of the web 18. These brokenreinforcing fibers cooperate with the staple fibers to maintain thelayers in proper relative relationship during processing of reinforcingmat 18 and in the use thereof as a reinforcement for a pultruded part.

[0128] Turning now to FIG. 10, the web 85 with multiple layers ofreinforcing fibers 71A, 71B, 71C, 71D and the layer of staple fibers 73is fed into a hydro-entangler 66 on a fine-mesh belt 76. In general, thehydro-entangler 66 has upper manifold structure 68 receiving water fromsupply source 70 provided with a plurality of openings or nozzles 72which direct water jets 74 directly onto the web. The water-jetsdelivered from nozzles 72 are preferably pulsed so that the jet streamsexit through respective nozzles 72 and pass through the thickness of theweb 85 until impacting the upper surface of a fine mesh belt 76. Thewater streams impacting against the upper surface of belt 76 cause thewater to dissipate and thereby spread the fibers carried by the jetstreams transversely across the top of the belt 76 to enhanceentanglement of the web 85.

[0129] A suitable hydro-entangler is commercially available from ICBTPerfojet of Mont Bonnet, France. The ICBT Perfojet hydro-entangler hasthree horizontally-spaced manifolds of the type shown schematically inFIG. 10, each having a row of water-jet nozzles 68, with the nozzlesspaced at approximately eight per inch, providing a total of 100 to 150nozzle openings. The water is jetted onto the web 85 with the firstmanifold set at a water pressure of 500 psig, the second at 1500 psig,and the third at 1500 psig. The web 85 becomes entangled as the waterjets from manifold 66 pass through the layered material making up thereinforcing mat 18.

[0130] The hydro-entangler has the capability to blow-in holes orenhance existing holes in the web 85 to achieve higher permeability.Permeability is useful to allow resin to flow through the thickness ofthe reinforcing mat in the pultrusion die, to avoid harmful hydraulicsor bubbling of the reinforcing mat at the pultrusion die entrance. Whenenhanced by hydro-entangling, the hole size and distribution aredetermined by the hydro-entangler back screen pattern and back screenmesh size.

[0131] A mesh size of 24×48 wires/inch in the backside conveyor beltthat transports the web 85 through the hydro-entangling process has beenused to create an array of holes 24×48 holes/inch², to increase thepermeability. A mesh size of 10×10 wires/inch can also be used for someapplications where the coarses mesh allows for larger holes,corresponding to a higher and more desirable permeability. Apermeability of 200-400 ft³/minute/ft² of air, through the web 85 (at apressure differential of 0.5′ of water) is sufficient for the resin topenetrate the reinforcing mat 18 during pultrusion, but a permeabilityof 600-800 ft³/minute/ft² or higher works very well for subsequentpultrusion processing. In an alternate embodiment, the hole size anddistribution is enhanced by a needling operation.

[0132] In lieu of using a hydro-entangler as described, a head (notillustrated) may be provided which supports a series of barbed needles142 as shown in FIG. 18. In this case, the layer of staple fibers 73should be opposite the points 142 a of the needles so that when thebarbed needle penetrate the mat, the barbs 142 b do not engage thefibers of the staple fibers 73. However, upon retraction of the barbedneedles 142, the barbs 142 b thereon engage certain of the relativelyshort fibers and pull all at least a portion of such fibers upwardlyinto the reinforcing fiber layers and to entangle the staple fibers withthe reinforcing layers.

[0133] Turning back to FIG. 9, the web 85 can optionally be fed into aneedler or perforator 108 that has a head 110 which supports a pluralityof parallel, relatively closely-spaced needles 112 (FIG. 17) locateddownstream of the hot rolls 106. The head 110 is reciprocated tosequentially direct the needles 112 through the reinforcing mat to forman array of perforations. The array includes perforations spaced bothlongitudinal and transversely so the series of needles across the widthof the web 85 are punched through the web 85 as it moves forwardly toprovide the required number of spaced perforations. The perforationsincrease the porous nature of the reinforcing mat 18 and allowpenetration of resin to bond through the reinforcing mat into thevarious components of the mat.

[0134] From 1 to about 5000 holes per square inch may be formed in theweb using perforator 108, but about 80 holes per square inch formed by#14 needle size is preferred in a rectangular grid pattern. The needler108 may be of conventional design which functions at a rate ofapproximately 20 cycles or reciprocations per second. The holes may beround or polygonal and generally are of a diameter what may becharacterized as pin holes. The hole pattern may be random, square,rectangular, close-packed-hexagonal, or similar configurations. Duringneedling, the needles can optionally be heated to about 160° F., by useof electric heat guns placed inside the needle box area, and blowing airthrough the length of the needle board.

[0135] The flow of viscous resin (such as polyester resin) through thereinforcing mat during the pultrusion process affects the speed ofpultrusion and the quality of the pultruded part. The permeability ofthe reinforcing mat is particularly important at the die entrance forboth a bath style and a resin-injection style of pultrusion.

[0136] Permeability is measured using the procedures disclosed in ASTMD737-96 Test Method for Air Permeability of Textile Fabrics, which isincorporated herein by references. The rate of air flow passingperpendicularly through a known area of fabric is adjusted to obtain aprescribed air pressure differential between the two fabric surfaces.From this rate of air flow, the air permeability of the fabric isdetermined. The pressure differential used was 0.5 inch column of water.

[0137] Reinforcement fiber mats which are parallel to the direction ofpultrusion typically have a permeability of at least about 180ft³/minute/ft². To obtain pultrusion speeds with 30% filler in theresin, permeability of 300-350 ft³/minute/ft² is preferred. Apermeability of about 300-350 ft³/minute/ft² can be achieved by using acoarse mesh entangler-belt in the hydro-entangler, so that a smallernumber of larger holes are created (in the range of about 50 holes persquare inch) to maximize the capability of polyester resin flow throughthe mat. For some applications, reinforcing mats with a permeabilityabove 350 ft³/minute/ft² meets can be used.

[0138] The web 85 is directed under a vacuum system 87 that draws mostof the water from the web 85. The substantially dried web 85 is thenpassed through a forced-air oven 89. The oven 89 is preferably operatedat a temperature between the glass transition temperature of the lowmelt and high melt staple fibers. The staple fibers preferably softenand bond, but do not flow sufficiently to reduce the permeability of thereinforcing mat 18.

[0139] In an alternate embodiment, the web 85 is passes between a pairof hot rolls 106 which act to further calender the reinforcing mat andalso to melt and activate the polyester fibers to provide a bondingaction. In one embodiment, the rolls 106 are smooth 12 inch diametersmooth rolls on a B. F. Perkins calender set at 120° C. with a minimumgap of 0.007 inches. The rolls 106 reduce the reinforcing mat thicknessand fuse the polyester material into the reinforcing mat 18.

[0140] A binder or an equivalent powdered, solvent, thermal or aqueousbased thermoplastic binder is optionally applied to the reinforcing mat18 by dispenser 113. The web picks up this binder, and is then squeezedthrough the rubber drying rolls 115 set at 30 psi, at the given speedper the needling process. Various binder materials can be applied to thereinforcing mat 18 to increase stiffness, such as corn starch, polyvinylacetate or similar binder material. In one embodiment, the bindermaterial is a reactive modified latex binder applied to the top surfaceof the reinforcing mat by an applicator which fills the intersticesbetween the layers of the mat.

[0141] Binder is applied at a concentration adequate to impart thedesired stiffness to the reinforcing mat for pultrusion handling andprocessing. The dry-mat stiffness may be tailored forease-of-processing. The reactive sites in the binder regulate theoccurrence of cross-linking within the binder upon drying, which rendersthose sited useless for the purpose of enhancing the strength of thepultrusion. Although a 10% reactive solution of Franklin Duracet X080binder has been found to be beneficial and therefore preferred forenhancement of production strength, the level of binder reactiveactivity may be varied to achieve particular processing strengths andproduct strengths desirable for particular products.

[0142] An adhesive binding material such as polyvinyl acetate in a watercarrier and containing about 20% to about 60% solids, corn starch orother adhesive material can be used to assist in interconnecting thestructure so that the entangled fibers are bonded to the fibers of thereinforcing layers and the fibers are bonded to each other. Generally,the binding agent is present in an amount in the range of 2% to 20% byweight (dry weight without water). However, the amount of binding agentis significantly reduced relative to conventional non-woven mats andthus the stiffness of the structure is very much reduced and thereforeimproved, allowing the reinforcing mat to bend to take up the complexshape of the part to be formed while restricting shear.

[0143] If the staple fibers and/or some of the reinforcing fibers have athermoplastic content, the binder can be reduced or omitted. Instead,the fibers are heated to provide some amount of heat bonding to eachother. In the arrangement shown in FIG. 9, some of the entangling fibersare of a high melting point so that they remain intact and thus act asentangling fibers, and some are of a lower melting point so that theyact as bonding fibers. In some embodiments where the binder is notrequired for structural purposes, it may still be used to increasestiffness.

[0144] The reinforcing mat passes through drying oven 114 that uses 200°F. air forced through the thickness to dry the mat. A suitable dryingoven is available from National Drying of Cary, N.C. Once dried, thefinished reinforcing mat 18 is stored on roll 82. The reinforcing mat 18can optionally be slit longitudinally to the desired width forpultrusion prior to storage on the roll 82.

[0145] The calendering, needling, and padding steps can be rearranged,processed multiple times, or omitted if the reinforcing layers arethermally bonded with a resin as explained in detail herein, dependingon the desired permeability, stiffness, and thickness required for themat, to optimize the pultrusion process, and the mechanical propertiesof the pultruded product. The reinforcing mat formation may also becarried out on-line with the pultrusion process so as to avoid thewinding and supply steps although in general this is unlikely to bepractical in many circumstances due to the different speeds of theprocessing lines.

[0146] The reinforcing mat 18 as described provides reinforcement whichhas sufficient structural strength in the longitudinal and sheardirections to ensure that it will be transported through the pultrusiondie without significant longitudinal deformation or skewing. This isattributable to the fact that the main bulk of the fibers are arrangedin the transverse direction to provide the finished product with therequired transverse strength. The number of fibers therefore necessaryfor a predetermined transverse strength is significantly reduced sincethe bulk of the fibers are arranged in the direction to maximize thestrength provided by each fiber.

[0147] Reinforcing mats of varying weight per square yard may befabricated in accordance with the present invention. Mats of 0.5-1.0ounces per square yard are useful for structural pultrusions with wallthickness of about 0.038 inches to unusually-high-strength pultrusionsthat are 0.090″ thick, although other sizes of reinforcing mat andpultrusions can be made using this technology. The internal integrity ofthe present reinforcing mat permit strips as small as 0.5 inches wide tobe slit without causing the reinforcing layers to delaminate.

[0148] For example, if G-150 yarns are used as the reinforcement layer,then a pultrusion wall thickness of 0.031″ or less is feasible whileretaining the required capability of a structural part havinglongitudinal strengths of approximately 40,000 psi, and transversestrengths of approximately 20,000 psi. On the other hand, much thickerglass fibers may be used to make thicker pultrusions with unusualhigh-strength, due to the orderliness of the fiber orientation in thetransverse direction.

[0149] In addition, multiple layers of the reinforcing mat are useful inthe production of high-strength products, to achieve enhanced physicalcapability in the pultruded parts, by use of this technology. Forexample, if two or three layers of the mats are used in a regularstructural pultrusion that is 0.25-inches thick, then the strength ofthe pultrusion can be increased in the transverse direction as much as200-400%. The transverse stiffness of the thick pultrusion may also beadjusted by a factor of 200-400%, thereby enhancing the longitudinalcapability of the pultrusion because the bucking strength of thecomposite pultruded profile is dramatically increased.

[0150] In addition, one side of a pultrusion may be provided withmultiple reinforcing mat layers, or a thick reinforcing mat may beemployed on the compression side of the pultrusion product, while theother side of the pultrusion may be provided with a single layer on thetensile side. In the case of a hollow or channel-profile pultrusion, theoutside of the part may be provided with a single or thin mat, while theinside of the pultruded part is provided with thicker or multiple layersof the reinforcement mats.

[0151] The stacking sequence of the layers of the reinforcing mat mayalso be varied to achieve the different or enhanced capabilities. Forexample, in lieu of the sequence of layers of the preferred embodimentof reinforcing mat construction as illustrated in FIGS. 19 and 20, thepermeable transport layer may be located against the outer face of thetransverse glass reinforcing fibers, between the transverse reinforcingfibers and an adjacent transport layer, or between the oppositelyinclined rovings.

[0152] Reinforcing Fibers

[0153] The reinforcing fibers and the longitudinal rovings arepreferably compatible with the resin matrix. As used herein, the phrase“compatible” in the context of a thermosetting resin or matrix refers tofibers and other components of a pultrusion laminate or part areselected or treated so that they facilitate penetration and essentiallycomplete wetting and impregnation of the fiber and component surfaces bythe thermosetting resin or matrix material, provide desired physicalproperties of the cured or finished laminate or part, are chemicallystable with the thermosetting resin or matrix material and are resistantto hydrolysis.

[0154] The primary reinforcing fiber and the longitudinal rovings usedin pultrusion are typically glass fibers. The 90° reinforcing fibers arepreferably a 900 yield E-glass fiber that has been treated with anorgano-silane composition to increase reinforcement-matrix interfacialstrength. The +/−45° oriented reinforcing fibers and the 0° directionreinforcing fibers are preferably G150′s (15000 yards per pound) with athermoplastic polyester resin sheathing available from Engineered YamsIncorporated of Fall River, Mass.

[0155] Glass reinforcing fibers can be replaced with carbon fibers toachieve higher stiffness, strength, or temperature capability. Graphitefibers may for example be Mitsubishi Pitch K13C2U, Hexcel PAN AS4, andAmoco PAN T300. Glass reinforcing fibers can also be replaced witharamid fibers for toughness or resilience, using for example TeijinTechnora or Kevlar type aramid fibers, with Kevlar type 29 being usefuland Kevlar type 49 being preferred. Polyester fibers may be substitutedfor glass fibers where extended elongation or toughness are requisiteproperties, or natural fibers (e.g. cotton, jute, hemp) for cost. Metaland ceramic fibers may also be used.

[0156] The reinforcing fibers may be enhanced to improve the capabilityof the mat, or to tailor the reinforcing mat to achieve improvedperformance, including changes in geometry, stacking, materials, surfacetreatments such as sizings, and binders. For example, the 0° reinforcingfibers and the +/−45° reinforcing fibers may be pre-coated with athermoplastic synthetic resin comprising an amide, a polyester, or asimilar sheath-like binder. When subjected to elevated temperature, thesheathing binder flows and thereby fuses the reinforcing fibers of allof the layers of the reinforcing mat together, thereby producing awindable pre-mat. In addition, acrylic, polyvinyl acetatec, or similaremulsions with cross-linkable sites may be deposited on thereinforcement fibers so that these fibers react in the pultrusioncomposite to enhance the mechanical properties of the reinforcing mat byreinforcement of the fiber/resin interface. Methods of making a coatedreinforcing fiber are disclosed in U.S. Pat. No. 4,058,581 (Park).

[0157] Enhancement of the glass fibers may be accomplished by additionof a surface treatment including an organosilane to the fiber surface toaugment the strength and durability of the final pultruded product. Theaddition of a coupling agent such as an organosilanes has been found toincrease the pultruded product physical properties, such as wet strengthretention. For example, application of an organosilane to G75 glassfiber yams used for the transport fibers results in a stronger and moredurable pultruded product. When an organosilane coating is added to thereinforcing fibers, improved results were obtained when a cationicamino-functional silane. Tris (2-methoxyethoxyvinylsilane) and3-methacrylopropyltrimethoxysilane are exemplary silanes.

[0158] The composition for treating preferably comprises a surfacetreatment containing one or more coupling agents selected from the groupconsisting of organo silane coupling agents, transition metal couplingagents, amino-containing Werner coupling agents and mixtures thereof.These coupling agents typically have dual functionality. Each metal orsilicon atom has attached to it one or more groups which can react withthe glass fiber surface and/or the components of the treatingcomposition. As used herein, the term “react” with respect to couplingagents refers to groups that are chemically attracted, but notnecessarily chemically bonded, to the glass fiber surface and/or thecomponents of the treating composition, for example by polar, wetting orsolvation forces. Examples of suitable compatibilizing or functionalgroups include epoxy, glycidoxy, mercapto, cyano, allyl, alkyl,urethano, halo, isocyanato, ureido, imidazolinyl, vinyl, acrylato,methacrylato, amino or polyamino groups.

[0159] Functional organo silane coupling agents are preferred for use inthe present invention. Examples of suitable functional organo silanecoupling agents include A-187 gamma-glycidoxypropyltrimethoxysilane,A-174 gamma-methacryloxypropyltrimethoxysilane and A-100gamma-aminopropyltriethoxysilane silane coupling agents, each of whichare commercially available from OSi Specialties, Inc. of Tarrytown, N.Y.The organo silane coupling agent can be at least partially hydrolyzedwith water prior to application to the glass fibers, preferably at abouta 1:3 stoichiometric ratio or, if desired, applied in unhydrolyzed form.

[0160] Suitable transition metal coupling agents include titanium,zirconium and chromium coupling agents. The amount of coupling agent canbe 1 to about 10 weight percent of the composition for treating on atotal solids basis.

[0161] Crosslinking materials, such as the aminoplasts discussed above,can also be included in the composition for treating. Non-limitingexamples of suitable crosslinkers include melamine formaldehyde, blockedisocyanates such as BAYBOND XW 116 or XP 7055, epoxy crosslinkers suchas WITCOBOND XW by Witco Corp., and polyesters such as BAYBOND XP-7044or 7056. The BAYBOND products are commercially available from Bayer ofPittsburgh, Pa. The amount of crosslinker can be about 1 to about 25weight percent of the composition for treating on a total solids basis.

[0162] The composition for treating can include one or more emulsifyingagents for emulsifying components of the composition for treating.Non-limiting examples of suitable emulsifying agents or surfactantsinclude polyoxyalkylene block copolymers, ethoxylated alkyl phenols,polyoxyethylene octylphenyl glycol ethers, ethylene oxide derivatives ofsorbitol esters and polyoxyethylated vegetable oils. Generally, theamount of emulsifying agent can be about 1 to about 20 weight percent ofthe composition for treating on a total solids basis.

[0163] The composition for treating can also include one or more aqueousdispersible or soluble plasticizers to improve flexibility. Examples ofsuitable non-aqueous-based plasticizers which are aqueous dispersibleplasticizers include phthalates, such as di-n-butyl phthalate;trimellitates, such as trioctyl trimellitate; and adipates, such asdioctyl adipate. An example of an aqueous soluble plasticizer isCARBOWAX 400, a polyethylene glycol which is commercially available fromUnion Carbide of Danbury, Conn. The amount of plasticizer is morepreferably less than about 5 weight percent of the composition fortreating on a total solids basis.

[0164] Fungicides, bactericides and anti-foaming materials and organicand/or inorganic acids or bases in an amount sufficient to provide theaqueous composition for treating with a pH of about 2 to about 10 canalso be included in the composition for treating. Water (preferablydeionized) is included in the composition for treating in an amountsufficient to facilitate application of a generally uniform coating uponthe strand. The weight percentage of solids of the composition fortreating generally can be about 5 to about 20 weight percent.

[0165] Staple Fibers and/or Cut Fibers

[0166] Staple and/or cut fibers for making the permeable transport layerinclude fibers from polymers such as randomly oriented, cut-staplepolyester fibers. The staple fibers can be loosely associated orarranged in a sheet or batting structure. The hydro-entangling jetsgrasp the staple and/or cut fibers and carry parts of the fibers intoand through the reinforcing fiber layers, thus effecting entanglementand attachment of the underlying reinforcing fiber layers. The staplefibers preferably have a relatively low resistance to bending so thatfibers may be moved downwardly by hydro-entanglement, by mechanicalstructure such as barbed needles, and the like.

[0167] Suitable staple fibers are polyester, although glass fibers ofreduced denier meeting the requisite flexibility requirements may bealso used as the staple fibers. The polyester material making uppermeable transport layer comprises a batting of a blend of about50%-70% Wellman 1.5 denier×1.5″ polyester staple fiber, and about30%-50% Kosa 1.5 denier by 1.5″ long bi-component fiber, crimped andbaled. The Kosa fiber gives the batting web a heat-fusible component,while the Wellman fiber enhances the consistency of the polyesterbatting and decreases shrink of the web during heat-fusing. After theblend is mixed, an opener filamentizes the fibers. The polyester battingin one embodiment has a density of about 60 grams/m² to about 300grams/m² and in another embodiment about 90 grams/m² to about 150grams/m². As used herein, “denier” refers to the mass of a fiber dividedby its length.

[0168] The polyester staple fibers can be replaced with polyethylenebatting, such as Honeywell Spectra 1000 or Honeywell Spectra 2000 fiber,or with a high strength polyethylene fiber such as Dyneema SK60 ofToyobo Company. A polyamide (nylon) batting may also be used.Furthermore, a textured, bi-component or crimped thermoplastic orreactive thermoset staple fiber, powder, or slurry; or combinations ofthe above fibers, powders, or slurries such as Kosa K90 and Wellmanpolyester staple fibers in water or preferably FIT and Wellman polyesterstaple fibers in water as used in paper making processes may beemployed.

[0169] Blends of these staple fibers, powders, and slurries may also beused to achieve desired levels of stiffness and fusability (high-shrinkfibers make the heat-fusion step more dynamic by causing meltingkinetics to focus on the crossover-points of the reinforcement fibers).A blend of low-melt-flow index and high-strength (high-melt-index)staple fibers achieve a distribution of reinforcing mat strengths, wherethe combination of melting kinetics (low-melt-index), and staple-fiberstrength (high-melt-index) was varied to provide increased reinforcingmat integrity (longitudinal strength and resistance to melting at thepultrusion die entrance and within the pultrusion die).

[0170] The filament diameter size, in a range of about 9 to 25 microns,and the effective bundle diameter size, in a range of about in a rangeof about 0.010-inches to about 0.10-inch, can be adjusted to achievevarious dimensions of pultrusion mat. The reinforcement layer can bemade very thin, by the use of G150 yams, or smaller. The strength of themat, and corresponding pultrusion, can be increased, but thedistribution of holes (for pultrusion resin wetting) might be lessened,depending on the evenness of the distribution of the G150 yarns. Thereinforcement reinforcing fibers may also be increased in size to 110yield glass fibers resulting in a bulkier reinforcing mat of lower cost.

[0171] Circular-Bending Stiffness

[0172] The reinforcement mats of the present invention have sufficientstiffness to be pulled without wrinkling and to maintain tracking(parallelism) to minimize distortion during processing, yet retainsufficient suppleness to allow the reinforcing mat to conform to theshape of the perimeter of the pultruded part.

[0173] The stiffness of the reinforcing mat is measured according to theprocedure of ASTM D4032-94 Standard Test Method for Stiffness of Fabricby the Circular Bend Procedure. ASTM D4032 evaluates the maximum forcerequired to push the fabric through an orifice in a platform. Themaximum force is an indication of the fabric stiffness or resistance tobending.

[0174] The reinforcing mat preferably has a circular-bending stiffnesswithin the range of about 4 Newtons (1 kilogram-meter/second²) to about15 Newtons. A reinforcing mat having a value of less than about 4Newtons generally does not track well in the pre-former ahead of thepultrusion die for a complex part. A reinforcing mat over about 15Newtons circular-bending stiffness has been found to be so stiff that itmay be difficult to shape in the pre-former. A circular-bendingstiffness of over about 15 Newtons also results in a preformedreinforcing mat that has undesirable wrinkles, or spans depressions,because the stiff reinforcing mat cannot follow the pre-form shaper. Thestiffness of the reinforcing mat can be readily adjusted by theconcentration and type of the binder used.

[0175] Mat Thickness

[0176] The mat thickness is measured by a tight squeeze of a digitalcalipers from Mitutoyo Corporation. Generally three readings were taken,at three different spots, and the average was recorded.

[0177] Mat Tensile Strength

[0178] The reinforcing mat preferably has a tensile strength in the 90°or transverse direction of about 200 lbs./inch as measured per ASTMD76-99. The reinforcing mat has a tensile strength in the 0° or pulldirection of at least 3 lbs./inch as measured per ASTM D76-99, and morepreferably at least 6 lbs./inch.

[0179] Measurements were taken on samples about 3 inches wide×6 incheslong (either longitudinal or transverse) prepared by marking off thearea and hand shearing. The samples were each pulled at a rate of about0.2 in/minute until failure. Load and elongation were recorded. Theaverage of four samples was recorded.

EXAMPLE 1

[0180] Thermally Bonded Reinforcing Mat

[0181] A reinforcing mat, in a resin matrix, that provides hightransverse strength on the exterior or interior surface of a pultrudedpart such as a sash stile or rail, or a pultruded frame head, sill, orjamb, or other products outside the fenestration industry. Thecross-section of the pultruded part is a matrix of thermosetting resinwith longitudinal and other-reinforcing fibers in the interior of theparts profile thickness. A first mat layer accounts for about 0.010inches of the thickness of the pultruded part, thelongitudinal-reinforcing fiber area is about 0.030″ thick, and theopposite mat layer is also about 0.010″ thick. The longitudinalreinforcing fibers are oriented in the 0° direction. These longitudinalfibers are mostly 675-yield (about 675 yards per pound) glassreinforcing fibers.

[0182] The reinforcing mat is a multi-layered structure, with thelongitudinal direction (e.g. the pull direction) designated as the 0°. Afirst layer includes a plurality of about 1800-yield glass reinforcingfibers in the transverse or 90° direction in the plane of thereinforcing mat set at about 10 courses per inch. A second layerincludes of a plurality of an amide, polyester or reactive sheathedfiber glass bundles spaced about 4 per inch in about the +/−45°directions in the plane of the reinforcing mat thermally bonded to thetransverse glass fibers. A third layer includes of a plurality of anamide, polyester or reactive sheathed fiber glass bundles spaced about 4threads per inch in about the 0° direction in the plane of thereinforcing mat thermally bonded to the transverse glass fibers. Afourth layer includes a plurality of polyester fibers that have at leastportions thereof which extend in the thickness direction through thethird, second and/or first layers to effect a connection therebetween,with a pre-entangled weight of about 32 grams per square meter.

[0183] In addition, the reinforcing mat includes holes primarily betweenthe transverse 1800-yield reinforcing fibers, like sieve-holes in thethrough-thickness direction, with the holes numbering about eighty persquare-inch in a generally rectangular grid pattern. A polyvinylacetate-based binder adheres the multiple layers and/or the intersticeswithin a given layer. The entire reinforcing mat thickness (slightlycompressed during thickness measurement) is approximately 0.010-inches.Further, the reinforcing mat includes a back-side withalternately-spaced 0° fibers as a third layer of a plurality of anamide, polyester or reactive sheathed glass fiber bundles spaced about 4per inch in about the 0° direction in the plane of the mat, thermallybonded to the transverse glass fibers.

EXAMPLE 2

[0184] Polyester Stitched Reinforcing Mat

[0185] A reinforcing mat, in a resin matrix, that provides hightransverse strength on the exterior or interior surface of a pultrudedpart such as a sash stile or rail, or a pultruded frame head, sill, orjamb, or other products outside the fenestration industry. Thecross-section of the pultruded part is a matrix of thermosetting resinwith longitudinal and other-reinforcing fibers in the interior of theparts profile thickness. A first mat layer accounts for about 0.010inches of the thickness of the pultruded part, thelongitudinal-reinforcing fiber area is about 0.030″ thick, and theopposite mat layer is also about 0.010″ thick. The longitudinalreinforcing fibers are oriented in the 0° direction. These longitudinalfibers are mostly 675-yield (about 675 yards per pound) glassreinforcing fibers.

[0186] The reinforcing mat is a multi-layered structure, with thelongitudinal direction (e.g. the pull direction) designated as the 0°. Afirst layer includes a plurality of about 1800-yield glass fibersreinforcing fibers substantially in the transverse or 90° direction inthe plane of the mat, set at about 10 courses per inch. A second layerincludes a plurality of about 6-denier polyester thread spaced at about6 threads per inch in the +45° directions in the plane of the mat isstitched to the transverse glass fibers. A third layer includes aplurality of about a 6-denier polyester thread spaced about 6 per inchin about the 0° direction in the plane of the reinforcing mat stitchedto the transverse glass fibers. A fourth layer includes of a pluralityof about 6-denier fibers that have at least portions thereof that extendin the thickness direction through the third, second and/or first layersto effect a connection therebetween with a pre-entangled weight of about32 grams per square meter.

[0187] In addition, the reinforcing mat includes holes primarily betweenthe transverse 1800-yield reinforcing fiber with about eighty persquare-inch in a rectangular grid pattern. A polyvinyl acetate-basedbinder adheres the multiple layers and/or the interstices within a givenlayer. The entire reinforcing mat thickness (slightly compressed duringthickness measurement) is about 0.010 inches.

[0188] The back-side of the reinforcing mat includes altemately-spaced0° fibers as a third layer of a plurality of about a 6-denier polyesterthread spaced about 6 threads per inch in about the 0° direction in theplane of the reinforcing mat and stitched to the transverse glassfibers.

EXAMPLE 3

[0189] Glass Fiber Stitched Reinforcing Mat

[0190] A reinforcing mat, in a resin matrix, that provides hightransverse strength on the exterior or interior surface of a pultrudedpart such as a sash stile or rail, or a pultruded frame head, sill, orjamb, or other products outside the fenestration industry. Thecross-section of the pultruded part is a matrix of thermosetting resinwith longitudinal and other-reinforcing fibers in the interior of theparts profile thickness. A first mat layer accounts for about 0.010inches of the thickness of the pultruded part, thelongitudinal-reinforcing fiber area is about 0.030″ thick, and theopposite mat layer is also about 0.010″ thick. The longitudinalreinforcing fibers are oriented in the 0° direction. These longitudinalfibers are mostly 675-yield (about 675 yards per pound) glassreinforcing fibers.

[0191] The reinforcing mat is a multi-layered structure, with thelongitudinal direction (e.g. the pull direction) designated as the 0°. Afirst layer includes a plurality of about 1800-yield fiberglass fibersreinforcing fibers substantially in the transverse or 90° direction inthe plane of the reinforcing mat set at about 10 courses per inch. Asecond layer includes a plurality of glass fiber bundles spaced about 4per inch in about the +45° directions in the plane of the mat, stitchedto the transverse fiberglass. A third layer includes of a plurality ofabout a 6-denier polyester thread spaced at about 4 threads per inch inthe 0° direction in the plane of the reinforcing mat and stitched to thetransverse glass fibers. A fourth layer includes a plurality ofpolyester fibers that have at least portions thereof that extend in thethickness direction through the third, second and/or first layer toeffect a connection therebetween with a pre-entangled weight of about 32grams per square meter.

[0192] The reinforcing mat also includes holes primarily between thetransverse 1800-yield reinforcing fiber numbering about eighty persquare-inch in a rectangular grid pattern. A polyvinyl acetate-basedbinder adheres the multiple layers and/or the interstices within a givenlayer. The entire reinforcing mat thickness (slightly compressed duringthickness measurement) is about 0.010 inches. The reinforcing mat alsoincludes a back-side with altemately-spaced 0° fibers as a third layerof a plurality of a fiberglass bundles spaced about 4 threads per inchin the 0° direction in the plane of the reinforcing mat and stitched tothe transverse fiberglass.

EXAMPLE 4

[0193] Heat-Fused Polyester Stitched Reinforcing Mat

[0194] A reinforcing mat, in a resin matrix, that provides hightransverse strength on the exterior or interior surface of a pultrudedpart such as a sash stile or rail, or a pultruded frame head, sill, orjamb, or other products outside the fenestration industry. Thecross-section of the pultruded part is a matrix of thermosetting resinwith longitudinal and other-reinforcing fibers in the interior of theparts profile thickness. A first mat layer accounts for about 0.010inches of the thickness of the pultruded part, thelongitudinal-reinforcing fiber area is about 0.030″ thick, and theopposite mat layer is also about 0.010″ thick. The longitudinalreinforcing fibers are oriented in the 0° direction. These longitudinalfibers are mostly 250-yield (about 250 yards per pound) glassreinforcing yam.

[0195] The reinforcing mat is a multi-layered structure, with thelongitudinal direction (e.g. the pull direction) designated as the 0°.The first layer includes a plurality of about 1800-yield fiberglassfibers reinforcing fibers substantially in the transverse or 90°direction in the plane of the reinforcing mat set at about 8 courses perinch. A second layer includes a plurality of about G150 glass reinforcedyam spaced about 4 threads per inch in about the +/−45° directions inthe plane of the reinforcing mat adjacent to the transverse fiberglass.A third layer includes a plurality of about a 150-denier polyesterthread spaced about 5 threads per inch in the 0° direction in the planeof the reinforcing mat and stitched through all the layers. The bobbinthread was G150 glass reinforced yam. The fourth layer includes aplurality of polyester staple fibers that have at least portions thereofthat extend in the thickness direction through the third, second and/orfirst layer to effect a connection therebetween with a pre-entangledweight of about 60 grams per square meter. The polyester staple fibersare heat-fused at a temperature of about 350° to the glass reinforcedyams to act as an interlaminae-connector to the continuous fiber layers.

[0196] The reinforcing mat also includes holes primarily between thetransverse 1800-yield reinforcing fiber numbering about fifty persquare-inch in a rectangular grid pattern. A reactive modified latexbinder adheres the interstices between the layers. The entirereinforcing mat thickness (compressed during thickness measurement) isabout 0.010″.

EXAMPLE 5

[0197] Heat-Fused Smooth-Surface Polyester Stitched Reinforcing Mat

[0198] A reinforcing mat, in a resin matrix, that provides hightransverse strength on the exterior or interior surface of a pultrudedpart such as a sash stile or rail, or a pultruded frame head, sill, orjamb, or other products outside the fenestration industry. Thecross-section of the pultruded part is a matrix of thermosetting resinwith longitudinal and other-reinforcing fibers in the interior of theparts profile thickness. A first mat layer accounts for about 0.010inches of the thickness of the pultruded part, thelongitudinal-reinforcing fiber area is about 0.030″ thick, and theopposite mat layer is also about 0.010″ thick. The longitudinalreinforcing fibers are oriented in the 0° direction. These longitudinalfibers are mostly 250-yield (about 250 yards per pound) glassreinforcing yam.

[0199] The reinforcing mat is a multi-layered structure, with thelongitudinal direction (e.g. the pull direction) designated as the 0°. Afirst layer includes a plurality of about 1800-yield glass reinforcingfibers substantially in the transverse or 90° direction in the plane ofthe reinforcing mat set at about 8 courses per inch. A second layerincludes a plurality of about G150 glass reinforced yam spaced about 4courses per inch in the +/−45° directions in the plane of thereinforcing mat adjacent to the transverse glass fibers. A third layerincludes of a plurality of a about 150-denier polyester thread spacedabout 5 per inch in the 0° direction in the plane of the reinforcing matand stitched through all the layers mentioned above. The bobbin threadwas G150 glass reinforced yam. A fourth layer includes of a plurality ofpolyester staple fibers that have at least portions thereof which extendin the thickness direction through the third, second and/or first layerto effect a connection therebetween with a pre-entangled weight of about120 grams per square meter. The polyester staple fibers are heat-fusedat a temperature of about 350° to the glass reinforced yams to act as aninterlaminae-connector to the continuous fiber layers.

[0200] The reinforcing mat includes holes primarily between thetransverse 1800-yield reinforcing fiber numbering fifty holes persquare-inch in a rectangular grid pattern. A reactive modified latexbinder adheres the interstices between the layers. The entirereinforcing mat thickness (compressed during thickness measurement) isabout 0.010″.

EXAMPLE 6

[0201] Heat-Fused Stitchless Reinforcing Mat

[0202] A reinforcing mat, in a resin matrix, that provides hightransverse strength on the exterior or interior surface of a pultrudedpart such as a sash stile or rail, or a pultruded frame head, sill, orjamb, or other products outside the fenestration industry. Thecross-section of the pultruded part is a matrix of thermosetting resinwith longitudinal and other-reinforcing fibers in the interior of theparts profile thickness. A first mat layer accounts for about 0.010inches of the thickness of the pultruded part, thelongitudinal-reinforcing fiber area is about 0.030″ thick, and theopposite mat layer is also about 0.010″ thick. The longitudinalreinforcing fibers are oriented in the 0° direction. These longitudinalfibers are mostly 250-yield (about 250 yards per pound) glassreinforcing yam.

[0203] The reinforcing mat is a multi-layered structure, with thelongitudinal direction (e.g. the pull direction) designated as the 0°. Afirst layer includes a plurality of 1800-yield fiberglass fibersreinforcing fibers substantially in the transverse or 90° direction inthe plane of the reinforcing mat set at about 8 courses per inch. Asecond layer includes a plurality of G150 fiberglass yam spaced about 4courses per inch in the +/−45° directions in the plane of thereinforcing mat adjacent to the transverse glass fibers. A third layerincludes a plurality of polyester staple fibers that have at leastportions thereof which extend in the thickness direction through thethird, second and/or first layer to effect a connection therebetweenwith a pre-entangled weight of about 120 grams per square meter. Thepolyester staple fibers are heat-fused at a temperature of about 350° tothe fiberglass yams to act as an interlaminae-connector to thecontinuous fiber layers.

[0204] The reinforcing mat also includes holes primarily between thetransverse 1800-yield reinforcing fiber numbering about fifty persquare-inch in a rectangular grid pattern. A reactive modified latexbinder adheres the interstices between the layers. The entirereinforcing mat thickness (compressed during thickness measurement) isabout 0.010″.

EXAMPLE 7

[0205] Heat-Fused Stitchless Reinforcing Mat, Without 45° ReinforcingFibers

[0206] A reinforcing mat, in a resin matrix, that provides hightransverse strength on the exterior or interior surface of a pultrudedpart such as a sash stile or rail, or a pultruded frame head, sill, orjamb, or other products outside the fenestration industry. Thecross-section of the pultruded part is a matrix of thermosetting resinwith longitudinal and other-reinforcing fibers in the interior of theparts profile thickness. A first mat layer accounts for about 0.010inches of the thickness of the pultruded part, thelongitudinal-reinforcing fiber area is about 0.030″ thick, and theopposite mat layer is also about 0.010″ thick. The longitudinalreinforcing fibers are oriented in the 0° direction. These longitudinalfibers are mostly 250-yield (about 250 yards per pound) glassreinforcing yam.

[0207] The reinforcing mat is a multi-layered structure, with thelongitudinal direction (e.g. the pull direction) designated as the 0°. Afirst layer includes a plurality of about 1800-yield fiberglass fibersreinforcing fibers substantially in the transverse or 90° direction inthe plane of the reinforcing mat set at about 8 courses per inch. Asecond layer includes a plurality of polyester staple fibers that haveat least portions thereof that extend in the thickness direction throughthe third, second and/or first layer to effect a connectiontherebetween, with a pre-entangled weight of about 100-200 grams persquare meter. The polyester staple fibers are heat-fused at atemperature of about 350° to the glass reinforced yams to act as aninterlaminae-connector to the continuous fiber layers.

[0208] The reinforcing mat also includes holes primarily between thetransverse 1800-yield reinforcing fiber numbering about fifty persquare-inch in a rectangular grid pattern. A reactive modified latexbinder adheres the interstices between the layers. The entirereinforcing mat thickness (compressed during thickness measurement) isabout 0.010″.

EXAMPLE 8

[0209] Heat-Fused Polyester Stitched Reinforcing Mat UsingSilane-Treated Yarn

[0210] A reinforcing mat, in a resin matrix, that provides hightransverse strength on the exterior or interior surface of a pultrudedpart such as a sash stile or rail, or a pultruded frame head, sill, orjamb, or other products outside the fenestration industry. Thecross-section of the pultruded part is a matrix of thermosetting resinwith longitudinal and other-reinforcing fibers in the interior of theparts profile thickness. A first mat layer accounts for about 0.010inches of the thickness of the pultruded part, thelongitudinal-reinforcing fiber area is about 0.030″ thick, and theopposite mat layer is also about 0.010″ thick. The longitudinalreinforcing fibers are oriented in the 0° direction. These longitudinalfibers are mostly 250-yield (about 250 yards per pound) glassreinforcing yam.

[0211] The reinforcing mat is a multi-layered structure, with thelongitudinal direction (e.g. the pull direction) designated as the 0°. Afirst layer includes a plurality of G37-yield glass reinforced yamstreated with organosilanes. The yams of the first layer aresubstantially in the transverse or 90° direction in the plane of thereinforcing mat set at about 8 courses per inch. A second layer includesa plurality of G150 fiberglass yam spaced about 4 courses per inch inthe +/−45-degree directions in the plane of the reinforcing mat adjacentto the transverse glass reinforced yams of the first layer. A thirdlayer includes a plurality of about a 100-denier polyester thread spacedabout 5 threads per inch in the 0° direction in the plane of thereinforcing mat and stitched through all the layers mentioned above. Thebobbin thread was a G150 glass reinforced yam. A fourth layer includes aplurality of polyester staple fibers that have at least portions thereofwhich extend in the thickness direction through the third, second and/orfirst layer to effect a connection there-between with a pre-entangledweight of about 60 grams per square meter. The polyester staple fibersare heat-fused at a temperature of about 350° to the glass reinforcedyams to act as an interlaminae-connector to the continuous fiber layers.

[0212] The reinforcing mat also includes holes primarily between thetransverse 1800-yield reinforcing fiber numbering about fifty persquare-inch in a rectangular grid pattern. A reactive modified latexbinder adheres the interstices between the layers. The entirereinforcing mat thickness (compressed during thickness measurement) isabout 0.010″.

EXAMPLE 9

[0213] Heat-Fused Polyester Stitched Reinforcing Mat with Metallic 45°Reinforcing Fibers

[0214] A reinforcing mat, in a resin matrix, that provides hightransverse strength on the exterior or interior surface of a pultrudedpart such as a sash stile or rail, or a pultruded frame head, sill, orjamb, or other products outside the fenestration industry. Thecross-section of the pultruded part is a matrix of thermosetting resinwith longitudinal and other-reinforcing fibers in the interior of theparts profile thickness. A first mat layer accounts for about 0.010inches of the thickness of the pultruded part, thelongitudinal-reinforcing fiber area is about 0.030″ thick, and theopposite mat layer is also about 0.010″ thick. The longitudinalreinforcing fibers are oriented in the 0° direction. These longitudinalfibers are mostly 250-yield (about 250 yards per pound) glassreinforcing yam.

[0215] The reinforcing mat is a multi-layered structure, with thelongitudinal direction (e.g. the pull direction) designated as the 0°. Afirst layer includes a plurality of 1800-yield glass reinforced fiberssubstantially in the transverse or 90° direction in the plane of thereinforcing mat set at about 8 courses per inch. A second layer includesa plurality of about 0.008″ diameter aluminum wire spaced about 4 wiresper inch in the +/−45° directions in the plane of the reinforcing matadjacent to the transverse fibers. A third layer includes a plurality ofabout a 100-denier polyester thread spaced about 5 threads per inch inthe 0° direction in the plane of the reinforcing mat and stitchedthrough all the layers mentioned above using a G150 glass reinforced yamas the bobbin thread. A fourth layer includes a plurality of polyesterstaple fibers that have at least portions thereof which extend in thethickness direction through the third, second and/or first layer toeffect a connection there-between, with a pre-entangled weight of about60 grams per square meter. The polyester staple fibers are heat-fused ata temperature of about 350° to the fiberglass yams to act as aninterlaminae-connector to the continuous fiber layers.

[0216] The reinforcing mat also includes holes primarily between thetransverse 1800-yield reinforcing fiber numbering about fifty persquare-inch in a rectangular grid pattern. A reactive modified latexbinder adheres the interstices between the layers. The entirereinforcing mat thickness (compressed during thickness measurement) isabout 0.010″.

EXAMPLE 10

[0217] Heat-Fused Polyester Stitched Reinforcing Mat without 45°Reinforcing Fibers

[0218] A reinforcing mat, in a resin matrix, that provides hightransverse strength on the exterior or interior surface of a pultrudedpart such as a sash stile or rail, or a pultruded frame head, sill, orjamb, or other products outside the fenestration industry. Thecross-section of the pultruded part is a matrix of thermosetting resinwith longitudinal and other-reinforcing fibers in the interior of theparts profile thickness. A first mat layer accounts for about 0.010inches of the thickness of the pultruded part, thelongitudinal-reinforcing fiber area is about 0.030″ thick, and theopposite mat layer is also about 0.010″ thick. The longitudinalreinforcing fibers are oriented in the 0° direction. These longitudinalfibers are mostly 250-yield (about 250 yards per pound) glassreinforcing yam.

[0219] The reinforcing mat is a multi-layered structure, with thelongitudinal direction (e.g. the pull direction) designated as the 0° .A first layer includes a plurality of about 1800-yield glass reinforcingfibers substantially in the transverse or 90° direction in the plane ofthe reinforcing mat set at about 8 courses per inch. A second layerincludes a plurality of about a 100-denier polyester thread spaced about5 per inch in the 0° direction in the plane of the reinforcing mat andstitched through all the layers mentioned above using a G150 glassreinforced yarn as the bobbin thread. A third layer includes a pluralityof polyester staple fibers that have at least portions thereof whichextend in the thickness direction through the third, second and/or firstlayer to effect a connection there-between, with a pre-entangled weightof about 120 grams per square meter. The polyester staple fibers areheat-fused at a temperature of about 350° to the fiberglass yams to actas an interlaminae-connector to the continuous fiber layers;

[0220] The reinforcing mat also includes holes primarily between thetransverse 1800-yield reinforcing fiber numbering about fifty persquare-inch in a rectangular grid pattern. A reactive modified latexbinder adheres the interstices between the layers. The entirereinforcing mat thickness (compressed during thickness measurement) isabout 0.010″.

[0221] The complete disclosures of all patents, patent applications, andpublications disclosed herein, including those cited in the Backgroundof the Invention section, are incorporated herein by reference as ifindividually incorporated. Various modifications and alterations of thisinvention will become apparent to those skilled in the art withoutdeparting from the scope and spirit of this invention, and it should beunderstood that this invention is not to be unduly limited to theillustrative embodiments set forth herein.

What is claimed is:
 1. A method of preparing a reinforcing structure foruse in manufacture a pultruded part where the reinforcing structure ispulled through a pultrusion die in a continuous longitudinal pulldirection, the method comprising the steps of: arranging a plurality offirst reinforcing fibers in a transverse direction; and attaching apermeable transport web of staple fibers to the first reinforcing fiberssuch that the portion of the first reinforcing fibers oriented in thedirection transverse comprises at least 40% of a volume of materialscomprising the reinforcing structure.
 2. The method of claim 1comprising arranging the plurality of first reinforcing fibers such thatthe portion of the first reinforcing fibers oriented in the directiontransverse to the pull direction comprises at least 50% of the volume ofthe materials comprising the reinforcing structure.
 3. The method ofclaim 1 comprising arranging the first reinforcing fibers into one ormore overlapping layers of first reinforcing fibers.
 4. The method ofclaim 1 comprising preparing the staple fibers to have a length of about½ inch to about 4 inches.
 5. The method of claim 1 comprising preparingthe staple fibers to have a length of about 0.01 inch to about 12inches.
 6. The method of claim 1 comprising preparing the staple fibersto have a weight of about 60 grams per square meter to about 300 gramsper square meter before attachment to the first reinforcing fibers. 7.The method of claim 1 comprising preparing the staple fibers to have aweight of about 10 grams per square meter to about 1200 grams per squaremeter before attachment to the first reinforcing fibers.
 8. The methodof claim 1 comprising preparing the permeable transport web fromheat-fusible fibers.
 9. The method of claim 1 comprising preparing thepermeable transport web from at least two different polymeric fiberseach with different glass transition temperature.
 10. The method ofclaim 9 wherein the at least two polymeric fibers comprise a glasstransition temperature of about 350° F. and about 270 ° F.,respectively.
 11. The method of claim 1 comprising preparing thepermeable transport web from a plurality of first polymeric fiberscomprising a first glass transition temperature, and a plurality ofbi-component fiber wherein a first component comprises the first glasstransition temperature, and a second component comprising a second glasstransition temperature less than the first glass transition temperature.12. The method of claim 11 wherein the bi-component fibers comprise acore-sheath configuration.
 13. The method of claim 1 wherein thereinforcing structure comprises in-plane mechanical and directionalstability.
 14. The method of claim 1 comprising randomly entangling atleast a portion of fibers in the permeable transport web with the firstreinforcing fibers.
 15. The method of claim 1 comprising thermallybonding at least a portion of fibers in the permeable transport web withthe first reinforcing fibers.
 16. The method of claim 1 comprisingattaching the first reinforcing fibers in a spaced-apart configurationwith a continuous stitching fiber.
 17. The method of claim 16 whereinthe stitching fiber comprises glass fibers, natural fibers, carbonfibers, metal fibers, ceramic fibers, synthetic or polymeric fibers,composite fibers including one or more components of glass, naturalmaterials, metal, ceramic, carbon, and/or synthetics components, or acombination thereof.
 18. The method of claim 1 comprising applying abinder to the permeable transport web and the first reinforcing fibers.19. The method of claim 18 wherein the binder comprises one or more of aspecialized latex binder diluted in a water carrier, a polyvinyl acetateemulsion, or a crosslinking polyvinyl acetate emulsion.
 20. The methodof claim 1 comprising forming a plurality of perforations through thepermeable transport web and between the first reinforcing fibers. 21.The method of claim 1 comprising preparing the permeably reinforcingsheet with a permeability of at least 180 ft³/minute/ft² as measuredaccording to the procedure of ASTM D737-96 with a pressure differentialof about 0.5 inch column of water.
 22. The method of claim 1 comprisingpreparing the permeably reinforcing sheet with a permeability of about300 ft³/minute/ft² as measured according to the procedure of ASTMD737-96 with a pressure differential of about 0.5 inch column of water.23. The method of claim 1 comprising preparing the permeably reinforcingsheet with a permeability of more than 350 ft³/minute/ft² as measuredaccording to the procedure of ASTM D737-96 with a pressure differentialof about 0.5 inch column of water.
 24. The method of claim 1 comprisingpreparing the permeably reinforcing sheet with a circular bendingstiffness of at least about 4 Newtons as measured according to theprocedure of ASTM D4032-94.
 25. The method of claim 1 comprisingpreparing the permeably reinforcing sheet with a circular bendingstiffness in a range of at least 4 Newtons to about 15 Newtons asmeasured according to the procedure of ASTM D4032-94.
 26. The method ofclaim 1 comprising preparing the permeably reinforcing sheet with athickness of about 0.004 inches to about 0.020 inches.
 27. The method ofclaim 1 comprising preparing the permeably reinforcing sheet with athickness of about 0.010 inches to about 0.012 inches.
 28. Thereinforcement structure of claim 1 comprising preparing the permeablyreinforcing sheet with a tensile strength in the transverse direction ofabout 200 lbs/inch as measured using the procedure of ASTM D76-99. 29.The reinforcement structure of claim 1 comprising preparing thepermeably reinforcing sheet with a tensile strength in the pulldirection of at least 6 lbs/inch as measured using the procedure of ASTMD76-99.
 30. The method of claim 1 comprising selecting the firstreinforcing fibers from a group consisting of glass fibers, naturalfibers, carbon fibers, metal fibers, ceramic fibers, synthetic orpolymeric fibers, composite fibers including one or more components ofglass, natural materials, metal, ceramic, carbon, and/or syntheticscomponents, or a combination thereof.
 31. The method of claim 1comprising preparing the first reinforcing fibers with at least onepolymeric component.
 32. The method of claim 1 comprising coating thefirst reinforcing fibers with a surface treatment including anorganosilane agent.
 33. The reinforcement structure of claim 32 whereinthe organosilane agent comprises one or more families of a cationicamino-functional silane, Tris (2-methoxyethoxyvinylsilane), or3-methacryloxypropyltrimethoxysilane.
 34. The method of claim 1comprising arranging the first reinforcing fibers in a direction about90°+/−10° relative to the pull direction.
 35. The method of claim 1comprising arranging the first reinforcing fibers in a direction about90°+/−5° relative to the pull direction.
 36. The method of claim 1comprising arranging substantially all of the first reinforcing fibersto extend continuously across a width of the reinforcing structure. 37.The method of claim 1 comprising attaching a plurality of permeabletransport webs to the first reinforcing fibers.
 38. The method of claim1 comprising arranging a plurality of second reinforcing fibers at oneor more acute angles relative to the pull direction.
 39. The method ofclaim 1 comprising arranging a plurality of second reinforcing fibers ata first acute angle relative to the pull direction and arranging aplurality of third reinforcing fibers at a second acute angle that isthe negative of the first acute angle.
 40. The method of claim 39comprising arranging a plurality of fourth reinforcing fibers in thepull direction.
 41. The method of claim 39 comprising locating the firstreinforcing fibers between the second and third reinforcing fibers. 42.The method of claim 1 comprising the steps of: arranging a plurality ofsecond reinforcing fibers at a first acute angle relative to the pulldirection; arranging a plurality of third reinforcing fibers at a secondacute angle that is the negative of the first acute angle; and arranginga plurality of fourth reinforcing fibers generally in the pulldirection.
 43. The method of claim 42 comprising randomly entangling atleast a portion of fibers in the permeable transport web with one ormore of the first, second, third or fourth reinforcing fibers.
 44. Themethod of claim 42 comprising thermally bonding at least a portion offibers in the permeable transport web with one or more of the first,second, third or fourth reinforcing fibers.
 45. The method of claim 42comprising stitching the first reinforcing fibers to one or more of thepermeable transport web, the second reinforcing fibers, the thirdreinforcing fibers, and the fourth reinforcing fibers.
 46. The method ofclaim 42 comprising applying a binder to the permeable transport web andto one or more of the first, second, third or fourth reinforcing fibers.47. The method of claim 42 comprising preparing one or more of thefirst, second, third or fourth reinforcing fibers with a polymericcomponent.
 48. The method of claim 42 comprising locating the firstreinforcing fibers between the second and third reinforcing fibers andthe fourth reinforcing fibers.
 49. The method of claim 42 comprisingpreparing the first, second, third or fourth reinforcing fibers asdiscrete layers.
 50. A method of preparing a reinforcing structure foruse in manufacture a pultruded part where the reinforcing structure ispulled through a pultrusion die in a continuous longitudinal pulldirection, the method comprising the steps of: arranging a plurality offirst reinforcing fibers generally in a transverse direction; preparinga permeably reinforcing sheet comprising a plurality of first polymericfibers comprising a first glass transition temperature and a pluralityof bi-component fiber wherein a first component comprises the firstglass transition temperature and a second component comprises a secondglass transition temperature less than the first glass transitiontemperature; and attaching a permeable transport web to the firstreinforcing fibers.
 51. A method of preparing a reinforcing structurefor use in manufacture a pultruded part where the reinforcing structureis pulled through a pultrusion die in a continuous longitudinal pulldirection, the method comprising the steps of: arranging a plurality offirst reinforcing fibers in a transverse direction relative to the pulldirection; and thermally bonding a permeably reinforcing sheet to thefirst reinforcing fibers so that the reinforcing structure comprises apermeability of at least 180 ft³/minute/ft² as measured according to theprocedure of ASTM D737-96 with a pressure differential of about 0.5 inchcolumn of water.
 52. A method of preparing a reinforcing structure foruse in manufacture a pultruded part where the reinforcing structure ispulled through a pultrusion die in a continuous longitudinal pulldirection, the method comprising the steps of: arranging a plurality offirst reinforcing fibers oriented in a transverse direction; andattaching a permeable transport web of staple fibers to the firstreinforcing fibers such that a ratio of a modulus of elasticity of thereinforcing structure in the transverse direction relative to a modulusof elasticity in the pull direction comprises at least 1.2.
 53. Themethod of claim 52 wherein the ratio of the modulus of elasticity of thereinforcing structure in the transverse direction relative to themodulus of elasticity in the pull direction comprises at least 1.5. 54.The method of claim 52 wherein the ratio of the modulus of elasticity ofthe reinforcing structure in the transverse direction relative to themodulus of elasticity in the pull direction comprises at least
 3. 55.The method of claim 52 wherein the ratio of the modulus of elasticity ofthe reinforcing structure in the transverse direction relative to themodulus of elasticity in the pull direction comprises at least
 5. 56. Amethod of preparing a reinforcing structure for use in manufacture apultruded part where the reinforcing structure is pulled through apultrusion die in a continuous longitudinal pull direction, the methodcomprising the steps of: arranging a plurality of non-overlapping firstreinforcing fibers in a transverse direction; and attaching a permeabletransport web of staple fibers to the first reinforcing fibers such thatthe portion of the first reinforcing fibers extending in a transversedirection comprises at least 30% of a volume of materials comprising thereinforcing structure.
 57. A method of preparing a reinforcing structurefor use in manufacture a pultruded part where the reinforcing structureis pulled through a pultrusion die in a continuous longitudinal pulldirection, the method comprising the steps of: arranging a plurality offirst reinforcing fibers at 45° (+/−15°) relative to the pull direction;arranging a plurality of second reinforcing fibers at −45° (+/−15°)relative to the pull direction; and attaching a permeable transport webof staple fibers attached to the first and second reinforcing fiberssuch that the first and second reinforcing fibers comprises at least 30%of a volume of materials comprising the reinforcing structure.
 58. Amethod of preparing a reinforcing structure for use in manufacture apultruded part where the reinforcing structure is pulled through apultrusion die in a continuous longitudinal pull direction, the methodcomprising the steps of: arranging a plurality of first reinforcingfibers at 60° (+/−15°) relative to the pull direction; arranging aplurality of second reinforcing fibers at −60° (+/−15°) relative to thepull direction; and attaching a permeable transport web of staple fibersattached to the first and second reinforcing fibers such that the firstand second reinforcing fibers comprises at least 30% of a volume ofmaterials comprising the reinforcing structure.
 59. A method ofpreparing a reinforcing structure for use in manufacture a molded partwhere the reinforcing structure is located in a die having alongitudinal axis, the method comprising the steps of: arranging aplurality of first reinforcing fibers in a transverse direction; andattaching a permeable transport web of staple fibers to the firstreinforcing fibers such that the portion of the first reinforcing fibersoriented in the direction transverse comprises at least 40% of a volumeof materials comprising the reinforcing structure.
 60. A method ofpreparing a reinforcing structure for use in manufacture a pultrudedpart where the reinforcing structure is pulled through a pultrusion diein a continuous longitudinal pull direction, the method comprising thesteps of: arranging a plurality of first reinforcing fibers in atransverse direction continuously across a width of the reinforcingstructure; and attaching a permeable transport web of staple fibers tothe first reinforcing fibers.